What Size Fence Post Do I Need for a 6ft Fence?

If you are installing a 6ft fence, choosing the correct fence post size is one of the most important parts of planning the job. A post needs to support the full height and weight of the fencing above ground while also extending far enough below ground to create a strong, stable foundation.

For a typical fencing system with a finished height of approximately 6ft, an 8ft fence post is normally the correct starting point. This gives you approximately 6ft above ground and around 2ft of post below ground.

However, there is an important difference between a 6ft finished fence and a 6ft fence panel installed on top of a gravel board. Once you add a gravel board beneath the panel, the overall height of the fencing system increases. For this type of installation, a 9ft fence post will normally be required.

This guide explains the difference in detail, including concrete and timber posts, gravel boards, post depth, overall fence height and the common mistakes to avoid when ordering fencing materials.

Quick Answer: What Size Fence Post Do I Need for a 6ft Fence?

As a simple guide, Sky Fencing uses the following post heights when planning common panel fencing systems:

The important thing to remember is that you should choose your fence post based on the complete finished height of the fencing system, not simply the height of the fence panel.

You can view the different post options available in our fence posts range.

Why Does a 6ft Fence Need an 8ft Post?

A fence post needs to extend below ground level. If you installed a 6ft panel using a post that was only 6ft long, there would be no meaningful length available to secure the post into the ground.

An 8ft post provides the additional length required for the underground section of the installation.

For a straightforward fencing system finishing at approximately 6ft above ground, this commonly means:

• Approximately 6ft of the post remains above ground.
• Approximately 2ft of the post is installed below ground.

The below-ground section provides the foundation that helps the post resist movement caused by the weight of the fencing, wind loading and general use.

This is particularly important with a 6ft fence because taller fencing presents a much larger surface area to the wind than a low garden boundary.

Fence Panel Height and Finished Fence Height Are Not Always the Same

This is one of the easiest mistakes to make when ordering fencing materials.

A customer may say:

“I am installing a 6ft fence, so I need posts for a 6ft panel.”

But there are actually two different measurements to consider:

• The height of the fence panel itself.
• The finished height of the entire fencing system.

If a 6ft panel is installed without anything underneath it, the overall fencing height may be approximately 6ft.

If the exact same 6ft panel is installed above a gravel board, the finished fence becomes taller.

The post therefore has to accommodate:

• The fence panel.
• The gravel board.
• Any required clearance or positioning.
• The section of post installed underground.

This is why simply ordering posts based on the panel height can result in the wrong materials arriving for the job.

What Size Post for a 6ft Fence With a Gravel Board?

If you are installing a 6ft fence panel above a gravel board, Sky Fencing would normally move up to a 9ft fence post.

This is because the gravel board increases the total height of the fencing above ground.

For example, a 6ft panel installed above a 6 inch gravel board creates an overall fencing system taller than 6ft. A 12 inch gravel board increases the finished height even further.

The post needs to accommodate that extra height while still retaining sufficient length for installation below ground.

You can browse our range of gravel boards alongside the available posts when planning the complete system.

Why Use Gravel Boards?

Gravel boards sit between the bottom of the fence panel and the ground.

Their main purpose is to prevent the fence panel itself from sitting directly against soil, grass and other damp ground conditions.

This is particularly useful with timber fence panels because keeping the bottom of the panel away from constant ground contact can help protect the lower section of the fencing.

Gravel boards can also help create a neat, consistent base underneath a run of fencing.

They are commonly available in both concrete and timber versions, and the choice of gravel board can affect the overall appearance of the finished fence.

However, because the gravel board sits underneath the panel, its height must be included when calculating the post length.

6 Inch vs 12 Inch Gravel Boards With a 6ft Fence

Two common gravel board heights are approximately 6 inches and 12 inches.

A 6 inch gravel board creates less additional height than a 12 inch gravel board, but both still need to be taken into account.

6ft Panel With a 6 Inch Gravel Board

A 6ft panel plus a 6 inch gravel board creates an overall nominal component height of approximately 6ft 6in before taking any installation tolerances into account.

This is already taller than a standard 6ft finished fencing system, so using an 8ft post would significantly reduce the amount of post available below ground.

For that reason, a 9ft post is the more appropriate choice for Sky Fencing's typical panel-and-gravel-board setup.

6ft Panel With a 12 Inch Gravel Board

A 6ft panel combined with a 12 inch gravel board creates an overall nominal component height of approximately 7ft.

Again, the post needs enough total length to accommodate the fencing above ground while leaving sufficient post below ground.

A 9ft post provides the additional length required for this type of system.

When designing taller fencing systems, you should also make sure the intended overall height is suitable for the location and project before beginning installation.

8ft Fence Post vs 9ft Fence Post

The difference between an 8ft and 9ft post might not sound significant, but that extra foot can make a major difference once gravel boards and full-height panels are included.

If you are unsure which post to choose, calculate the complete above-ground height first.

Do not begin with the post size and try to make the rest of the fencing fit around it.

How Deep Should a Post Go for a 6ft Fence?

For a typical 6ft fencing system using an 8ft post, around 2ft of the post is commonly available for installation below ground.

However, post depth should not be treated as an identical measurement for every possible installation.

The appropriate depth can be affected by factors including:

• Overall fence height.
• Post type.
• Ground conditions.
• Exposure to wind.
• Weight and construction of the fencing.
• Whether the ground has previously been disturbed.
• The design of the complete fencing system.

A substantial garden fence needs a stable foundation, so it is worth taking time to prepare the post holes correctly rather than rushing this part of the installation.

Why Ground Conditions Matter

Two identical fences can behave differently if they are installed in different ground conditions.

Firm, undisturbed ground can provide a very different foundation from loose soil, recently excavated ground or ground filled with rubble and other material.

This is why the post hole should be assessed as part of the installation rather than treating every garden as identical.

If the ground around the post cannot provide a stable foundation, the fence may move even if the correct height post has been purchased.

Correct post selection therefore needs to work together with proper ground preparation and suitable post concrete.

How Much Post Concrete Should You Use?

There is no single quantity that can be guaranteed for every post because the amount required depends on the dimensions of the hole, post size and ground conditions.

A wider or deeper hole will naturally require more material than a smaller one.

Sky Fencing supplies post concrete for securing fence posts, and it is worth calculating the total amount required for the complete run before starting the installation.

Running out of post concrete halfway through a fencing job can unnecessarily interrupt the work.

We will also be covering this subject separately in our guide to how many bags of post concrete are required per fence post.

Concrete Fence Posts for a 6ft Fence

Concrete fence posts are one of the most common choices for full-height garden fencing.

With a traditional slotted concrete fencing system, the fence panels and gravel boards sit between the slots in neighbouring posts.

This creates a system where the posts and gravel boards can remain in place if an individual panel eventually needs replacing.

For a fencing system finishing at around 6ft, an 8ft concrete post is commonly used.

If you are installing a full 6ft panel with a gravel board underneath it, a 9ft concrete post would normally be selected instead.

Our fence posts category contains the available concrete and timber options for different fencing projects.

Advantages of Concrete Posts

Concrete posts are popular because they create a durable fencing support system and do not rely on timber being installed directly into the ground.

They work particularly well with:

• Closeboard fence panels.
• Waney lap panels.
• Decorative fence panels where suitable.
• Concrete gravel boards.
• Other compatible panel fencing systems.

Slotted concrete posts can also make future panel replacement more straightforward because the panel can often be removed while the existing posts remain in position.

Timber Fence Posts for a 6ft Fence

Timber posts are another common option and provide a more traditional all-timber appearance.

The same basic principle applies: the post must be long enough to provide the required finished fence height while retaining sufficient length below ground.

For a finished fence around 6ft high, an 8ft timber post is commonly the appropriate starting point.

If additional components increase the finished height, a longer post may be required.

Timber posts are often selected for fencing systems where customers want the posts, rails and other visible structural components to retain a consistent timber appearance.

Concrete Posts vs Timber Posts for a 6ft Fence

Neither option is automatically right for every garden.

The best choice depends on the fencing system, preferred appearance, installation method and long-term plans for the boundary.

We will cover this comparison in greater detail in our dedicated concrete vs timber fence post guide.

What About a 5ft Panel With a Gravel Board?

This is where understanding finished height becomes particularly useful.

You do not necessarily need a 6ft panel to create a fence finishing around 6ft high.

For example, a 5ft panel combined with a 12 inch gravel board produces a nominal component height of around 6ft.

This may be preferable where a customer wants the protection and appearance of a deeper gravel board while keeping the overall fence close to a particular finished height.

It also demonstrates why the entire system should be planned together rather than choosing each component independently.

Choosing the Fence Panel Before the Post

It usually makes sense to decide what type and height of fencing you actually want before ordering your posts.

Your planning order might look like this:

1. Measure the boundary.
2. Choose the required finished fence height.
3. Select the fence panel type and height.
4. Decide whether gravel boards will be used.
5. Calculate the total above-ground height.
6. Select the appropriate post length.
7. Work out how many posts, panels and gravel boards are required.
8. Calculate the required amount of post concrete and fixings.

Planning the job in this order reduces the chance of buying posts that are too short for the chosen panel and gravel board combination.

What Type of Fence Panel Works With a 6ft Fence?

A wide range of fence panels are available in heights suitable for creating full-height garden boundaries.

You can browse the wider fence panels range to compare the available styles.

One of the most popular options is closeboard fencing because it creates a substantial, private timber boundary.

Sky Fencing's closeboard fence panels are manufactured in-house in Wickford and are available in a range of sizes for different fencing systems.

The post sizing principle remains the same regardless of panel style: calculate the full finished height before choosing the post.

Standard Closeboard and Heavy Duty Closeboard Fencing

If you are considering closeboard panels, there is also a choice between standard and Heavy Duty construction.

Sky Fencing's standard closeboard panels use approximately 47 x 32mm rails, while our Heavy Duty closeboard panels use larger 75 x 32mm rails.

Our appropriate closeboard panels use 19 vertical boards, while many competing alternatives use 18 boards.

We also use 50-micron hot-dipped galvanised nails in our closeboard panels to help resist premature rusting.

These panel construction details do not change the basic method of calculating post height, but they are important when choosing the complete fencing system rather than looking only at panel dimensions.

How Many Posts Do I Need for a 6ft Fence?

Once you know the correct post height, the next question is normally how many posts are required.

For a simple straight run of panel fencing, you generally need posts between the panels as well as a post at each end of the run.

The exact number depends on:

• The total boundary length.
• The width of the panels.
• Whether there are corners.
• Whether gates are included.
• Whether end, corner or specialist posts are required.
• The type of fencing system being installed.

Do not simply order the same quantity of posts as panels without considering the starting and finishing posts and any changes in direction.

What Happens if the Fence Post Is Too Short?

A post that is too short creates an immediate installation problem.

You may find that once the required panel and gravel board height has been allowed for, there is not enough post remaining to achieve the intended installation depth.

This can lead to customers trying to compromise either the finished height or the amount of post below ground.

The better approach is to calculate the required post length correctly before ordering.

Buying the longer post where the system genuinely requires it is much easier than trying to compensate for an undersized post once installation has begun.

Can a Fence Post Be Too Long?

A longer post gives more flexibility than a post that is too short, but this does not mean that buying the longest post available is always the best solution.

Fence components should be selected to suit the actual design.

Unnecessarily oversized posts may:

• Cost more.
• Be heavier to handle.
• Require different preparation.
• Be unnecessary for the fencing system being installed.

It is better to work out the correct size rather than automatically oversizing every component.

Do All Posts Along the Fence Need to Be the Same Height?

For a straightforward level run of fencing, the main intermediate posts would normally be selected to suit the same fencing system.

However, real gardens are not always perfectly level or completely straight.

A fencing run may include:

• Changes in ground level.
• Steps.
• Corners.
• Different panel heights.
• Gates.
• Existing structures.

These can affect how the fencing needs to be planned.

If the ground changes significantly across the run, calculate the required finished height at different points rather than assuming every section will behave exactly the same way.

Planning a Fence on Sloping Ground

Sloping gardens require additional thought because the ground level changes as the fencing progresses.

Depending on the fencing design, panels may be stepped rather than following the exact line of the slope.

This can change the amount of post visible above the ground at different points.

The key principle remains the same: each post must provide the required support for the fencing at its particular position.

Measure the site before ordering rather than relying purely on an estimated overall boundary length.

Measure Before You Order

Incorrect measurements are one of the easiest ways to end up with the wrong quantity or size of fencing materials.

Before ordering, measure the complete boundary and make a note of:

• Total length.
• Desired finished height.
• Existing ground levels.
• Changes in direction.
• Gate positions.
• Existing posts or structures.
• Any significant slopes.
• The panel and gravel board combination you intend to use.

Once these measurements are known, choosing the correct post height becomes much easier.

Example 1: Straightforward 6ft Fence

Imagine you want a garden boundary to finish at approximately 6ft high.

You select fencing that creates an overall above-ground height of approximately 6ft.

An 8ft post gives you the required above-ground height while providing additional length to install the post securely below ground.

This is the straightforward situation most people have in mind when asking what size fence post is required for a 6ft fence.

Example 2: 6ft Panel With a Gravel Board

Now imagine you buy a full 6ft panel but decide that you also want a gravel board underneath it.

Your fence is no longer only 6ft high.

The gravel board has increased the total height.

If you tried to use the same 8ft post, the additional above-ground height would reduce the amount of post available below ground.

For Sky Fencing's typical setup, this is where you would move to a 9ft post.

Example 3: 5ft Panel With a Gravel Board

Another approach might be to choose a shorter panel and use a gravel board to bring the finished fencing system up to the desired overall height.

For example, a 5ft panel combined with a 12 inch gravel board gives a nominal component height of around 6ft.

This can provide a useful alternative where you want a substantial gravel board without making the complete fence significantly taller than the intended boundary height.

Common Fence Post Sizing Mistakes

1. Ordering Posts Based Only on the Panel Height

This is probably the most common mistake.

A 6ft panel does not automatically mean the finished fence will be 6ft high.

If a gravel board sits underneath it, you must add that height to the calculation.

2. Forgetting About the Underground Section

The post has to extend into the ground.

You cannot use the entire post length above ground and still expect to create a secure installation.

3. Buying All the Materials Separately Without Planning the System

Panels, posts and gravel boards need to work together.

Choosing them independently increases the chance that the dimensions will not suit the intended finished fence.

4. Ignoring Ground Conditions

Correct post length is important, but so is the ground into which the post is being installed.

Loose or difficult ground may need greater consideration than a straightforward installation into firm ground.

5. Assuming Every Garden Is Level

Ground levels can change significantly across a boundary.

Take measurements at several points, particularly on sloping gardens.

6. Forgetting Corners and Gates

A perfectly straight fence run is relatively simple to calculate.

Once corners, returns or gates are included, additional posts or different post configurations may be required.

What Else Do You Need to Build a 6ft Fence?

A fence post is only one component of the finished installation.

Depending on the system you choose, a typical fencing project may require:

• Fence panels.
• Fence posts.
• Gravel boards.
• Post concrete.
• Suitable fixings and accessories.
• Gate components where required.

Working out the complete material list before starting can save repeated trips for additional supplies and reduce the risk of discovering halfway through the project that an important component has been missed.

Should I Choose My Gravel Board Before My Post?

Yes, ideally you should know which gravel board you intend to use before finalising the post length.

The gravel board forms part of the total above-ground fencing height, so its dimensions directly affect the amount of post required.

Your planning process should therefore consider the panel, gravel board and post as one complete system.

This is particularly important when using full-height 6ft panels.

Can I Use a 6ft Panel Without a Gravel Board?

Fence panels can be installed in different systems, but gravel boards are commonly used to keep the bottom of the panel away from direct ground contact.

If you choose not to use a gravel board, you still need to make sure the complete fencing system is correctly planned and that the bottom of the timber panel is not unnecessarily exposed to damp ground conditions.

The absence of a gravel board also changes the overall height calculation, which can affect the post length required.

Can I Replace Existing 6ft Panels and Keep the Old Posts?

Potentially, provided the existing posts are still sound, correctly positioned and compatible with the replacement panels.

One advantage of slotted concrete posts is that individual panels can often be removed and replaced without rebuilding the entire fence line.

Before buying replacement panels, measure:

• The distance between the posts.
• The available slot height.
• The existing gravel board.
• The panel height.

Do not assume an existing fence uses exactly the dimensions you expect without measuring first.

Should I Replace a Damaged Post or Use a Repair Spur?

If the issue is an existing damaged timber post rather than a completely new fence, replacing the whole post is not always the only potential repair method.

Concrete repair spurs are commonly used alongside suitable existing timber fencing where a timber post has failed near ground level but the rest of the fencing can remain serviceable.

The correct repair depends on the condition of the fence, and badly damaged or unstable fencing may require more extensive replacement.

We will cover repair spurs separately in our guide to what concrete repair spurs are and when they should be used.

Why Correct Post Size Matters More on Taller Fences

A low fence and a full-height privacy fence place very different demands on their posts.

As a fence becomes taller, the area exposed to the wind increases considerably.

This makes the posts and their foundations increasingly important.

The post is not simply there to hold the panel upright on a calm day. It forms part of the structural support system for the entire fencing run.

That is why it is worth getting the post height, depth and installation right from the start.

Planning Your Complete 6ft Fencing System

Before placing your order, work through these questions:

• What finished fence height do I actually want?
• What height panels am I using?
• Will I use gravel boards?
• If so, are they 6 inch or 12 inch?
• Will I use concrete or timber posts?
• How deep will the posts need to be installed?
• What are the ground conditions like?
• How many panels are required?
• How many posts are required?
• Are there any corners?
• Is a gate included?
• Does the ground slope?
• How much post concrete will be needed?

If you can answer those questions before ordering, you are far less likely to encounter sizing problems during installation.

So, What Size Fence Post Should I Buy for a 6ft Fence?

For a typical fencing system with a finished height of approximately 6ft, an 8ft fence post is normally the appropriate starting point.

If you are using a full 6ft panel with a gravel board underneath it, the complete fencing system becomes taller, so a 9ft post would normally be required.

The simplest rule is:

Do not choose your post based only on the number written on the fence panel. Calculate the complete finished height of the panel and gravel board first, then allow sufficient post length below ground.

Sky Fencing supplies a range of fence posts, gravel boards, fence panels and post concrete for complete fencing projects.

If you are considering traditional closeboard fencing, you can also explore our closeboard fence panels, which are manufactured in-house by Sky Fencing in Wickford.

Frequently Asked Questions

Is an 8ft post suitable for a 6ft fence?

Yes. For a fencing system finishing at approximately 6ft above ground, an 8ft post is commonly suitable because the additional post length can be installed below ground.

Do I need a 9ft post for a 6ft fence panel?

If the 6ft panel is being installed above a gravel board, a 9ft post will normally be required because the gravel board increases the total height of the fencing system.

What size concrete post do I need for a 6ft fence?

An 8ft concrete post is commonly used where the finished fencing height is approximately 6ft. A 6ft panel combined with a gravel board will normally require a 9ft post.

What size timber post do I need for a 6ft fence?

An 8ft timber post is a common starting point for a fencing system finishing at around 6ft, provided the installation and ground conditions are suitable. Additional above-ground height may require a longer post.

How much of an 8ft fence post goes into the ground?

With a straightforward fencing system finishing around 6ft high, approximately 2ft of an 8ft post is commonly available below ground. Actual installation requirements can vary with the fencing system and ground conditions.

Does a 6ft panel plus a gravel board equal a 6ft fence?

No. A 6ft panel already measures approximately 6ft high. Adding a gravel board underneath it increases the overall height of the fencing system.

What post do I need for a 6ft panel and 6 inch gravel board?

A 6ft panel plus a gravel board increases the total above-ground height beyond 6ft, so Sky Fencing would normally use a 9ft post for this type of setup.

What post do I need for a 6ft panel and 12 inch gravel board?

A 6ft panel plus a 12 inch gravel board creates a nominal component height of around 7ft. A 9ft post would normally be used to accommodate the increased fencing height while providing post length below ground.

Can I use an 8ft post with a 6ft panel and gravel board?

This would reduce the amount of post available below ground because the gravel board increases the overall above-ground height. For Sky Fencing's typical 6ft panel and gravel board system, a 9ft post is the appropriate choice.

Are concrete posts better than timber posts?

They suit different fencing systems. Concrete posts are popular for durability and slotted panel systems, while timber posts provide a traditional timber appearance. The best option depends on your project and preferred fencing style.

Do I need gravel boards with fence panels?

Gravel boards are commonly used beneath timber fence panels to keep the bottom of the panel away from direct ground contact and create a defined base to the fencing system.

How do I know how many fence posts I need?

The number of posts depends on the length of the boundary, panel widths, corners, gates and the type of fencing system. Remember that a straight run usually requires a post at both the beginning and end as well as posts between panels.

Should I measure the garden before ordering fence posts?

Yes. Measure the complete boundary, ground levels, corners and gate positions before ordering. You should also decide the panel and gravel board combination before selecting post lengths.

Can I use existing concrete posts with new fence panels?

Often yes, provided the posts remain stable, correctly spaced and compatible with the replacement panels. Measure the existing openings carefully before ordering new panels.

What other materials do I need for a 6ft fence?

A typical panel fencing system may require fence panels, posts, gravel boards, post concrete and suitable fixings. Gates, corners and other features may require additional components.