Whether you're installing a new fence or replacing an old one, taking accurate measurements ensures you get the right materials, avoid miscalculations, and keep your project on track. In this guide, we'll walk you through the essential steps for measuring a new post-and-rail fence so you can get it right from the start.

Establish Your Property Boundary:

If your post and rail fencing is being used for internal purposes, i.e. not on the boundary, you don’t have to worry about your boundary locations and are free to design the layout however you like. However, if your post and rail fence is going on your boundary, which is the most common place for a timber fence, the first step in measuring up is to establish the boundary of your property.

If you are replacing an existing fence, this will generally be a very clear indicator of the boundary. If your property is in a relatively new subdivision, you may also be able to locate the survey pegs. Survey pegs are 50x50mm timber pegs that are hammered flush with the ground and painted white.

If you are measuring the fence for the purpose of a quote/budgeting, then measuring approximate to the boundary is ok. However, if this is for the purpose of installing your fence and you are having trouble locating the boundary, it may be a good idea to get a surveyor in to reestablish the boundary for you. A surveyor will accurately mark out the boundary and place new location pegs so you know the fence is in the correct location.

Work Out the Layout and Details of the Fence:

The next step is to work out the layout and specs of your new fence. For a boundary fence, the layout will be quite easy to determine. Here are a few things to consider when planning the layouts:

Vehicle access gates: Where and how wide do you want these to be?
Gate setbacks: Do you want the gates set back from the main fence line to allow cars and trailers to pull off the road before the gates open?
Pedestrian access: Do you need any pedestrian or mower access through the fence?
Gardens and hedges: Are you planning to plant a garden or a hedge next to your post and rail?

When working out the style of your timber fence, this comes down to personal preference as well as the purpose of the fence. Some things to consider here are:

Is the fence just for aesthetics?
Do you need to keep dogs, pets or livestock in or pests out?
Do you need to keep children in?

Measuring the Fence and Working Out Material Quantities:

There are three main steps to measuring your post and rail fence:

Step #1 — Draw a sketch:

This is pretty simple. Sketch out the layout of your fence—it doesn't need to be to scale—similar to the image below:

fence layout sketch — Fence layout sketch

Step #2 — Measure the fenceline:

With your sketch in hand and a measuring wheel (or a long tape if the fence is a short run), you are ready to measure the fence.

Work your way around the fenceline, measuring each run of fencing from point to point. Also, make sure you measure the width of the gate openings. If these are beside a concrete driveway or edging, they may need to be exact. However, in most cases, as a new fence is being placed, there will be ‘wiggle room’ for the gate opening widths. To keep things simple, in the following example, we are going to leave out the gate width:

Step #3 — Work out the material quantities:

Now that we have the dimensioned sketch, you are ready to work out the quantity of required materials. If you are confident with this, you can go ahead and follow the steps below. If you aren’t confident, don’t worry. You can submit your sketch to Strukta via our online form or call us, and we can help you work this out.

First, you need to determine how many fencing bays there will be. To do this, we use the following simple calculation:

Steps	Calculation	Example
Step 1: Work out the quantity of bays	Length of fence section ÷ 2.4 (post spacings)	26m ÷ 2.4 = 10.833
Step 2: Round up to the nearest whole number	Round the result from Step 1	10.833 → 11 bays

Make a note of the quantity of bays on the sketch, and then repeat the calculation for all remaining sections of the fence.

Fence layout sketch with the quantity of bays

We then add the bay quantities together to get the total number of bays. In this example, the total quantity is 33 bays.

The number of rails required is calculated by multiplying the total bay quantity by the number of rails in the chosen fence style (e.g., 2-rail, 3-rail, 4-rail). For our example, we are using a 3-rail style. So, 33 bays x 3 rails = 99 rails required.

We now need to work out the quantity of posts required. To do this, we need to make sure we add an extra post for the end of the fence and an additional post for every opening in the fence. In this example, there is one opening, so we are going to add 1 extra post for the gate opening and 1 extra post for the end of the fence. This gives us 33 bays + 2 extra posts = 35 posts total.

Multiplication sketch showing the total junction and intermediate posts required

Now that we know the total number of posts needed, the next step is to determine the types of posts required. In this example, we have 7 junction posts. A junction post refers to any post that isn’t an intermediate post. These are typically used as gate posts, end posts, corner posts (both 90° and 45°), or ‘T’ posts. By subtracting the number of junction posts from the total, we can calculate how many intermediate posts are needed.

Congratulations, you have now worked out exactly what materials you need for your new post-and-rail fence. You can now work out a rough estimate of the project cost using our Pricing Guide or request an accurate quote from Strukta.

If you’re after a different style of fencing, such as paling or picket fencing, you can use the same steps to work out the material quantities. You may need to tweak it a bit to suit the post-spacings and infill material, but the general principle remains the same.

Get Started on Your New Post and Rail Fence

Getting your measurements right is the foundation of a strong and well-built fence. By following these steps when measuring for a new post and rail fence, you’ll ensure you have the correct materials, stay within budget, and avoid unnecessary delays. Proper planning makes installation smoother and helps build a durable fence that stands the test of time.

If you're ready to start your project, explore our post and rail fencing range for high-quality materials suited to your needs. For expert advice or assistance, contact our team—we're happy to help!

REQUEST A QUOTE

How To Measure For A New Post And Rail Fence