how to measure stair carpets

How To Measure Stair Carpets

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Homeowners often think it’s too difficult to do anything with their stairs. They’re not confident enough to try replacing their stair carpet themselves, and getting carpet fitted by a professional can be expensive, as we recently explained in our guide to carpet fitting costs.

The fact is that sorting out your stair carpet isn’t as tough as you may think. It starts with making accurate measurements for any new carpet, which is what this simple step-by-step (sorry, pun intended) guide is going to cover.

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Time

Difficulty


Tools List

  • Tape measure
  • Pencil and paper
  • Calculator (if you don’t trust your mental maths)

Instructions

As with many jobs, preparation is key to fitting stair carpet. That starts with making an accurate measurement of how much carpet you need.

When you get to actually fitting the carpet and find you don’t have enough, there’s very little you can do. That’s why our method relies on the idea of measuring twice and cutting once.

Preparing the Stairs

preparing stairs for new carpet

You’re looking for an accurate measurement of the floor area you need to cover with your new carpet. To get that, you need to measure the bare stairs themselves. Before you get to measuring, therefore, you need to take up any existing carpet and strip things back.

Taking up carpet from the stairs is a little more difficult than elsewhere. You can learn all the tips and tricks that make it much easier from this handy video guide:

Measuring a Tread

measuring a tread for new carpet

The first step to finding out exactly how much carpet you need for your stairs involves measuring each tread. The tread is the flat horizontal part of each step, which you stand on when using the stairs. Use a tape measure, take an accurate measurement of the width and depth of the tread.

If the tread on your stairs overhangs the riser (the vertical part), you need to account for this. Measure round the overhanging edge of the tread and add it to the depth measurement.

Write down the exact measurements. Then round up each figure to the nearest centimetre and write down those measurements, too.

Note: For each measuring step in this process, you should note down the exact measurements AND the rounded-up measurements. So two sets of measurements for each measurement. The exact measurements are used for the fitting stage and the rounded-up measurements are used when buying the carpet. Make sense? Good, let’s continue...

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Pro Tip: You don’t need to measure the full width of the tread if you’re going to use a runner rather than a full stair carpet. In that case, only measure the width of the tread which the runner will cover.

A stair runner can be an attractive interior design choice, as explained by Carpetright. If you are going to use one, some of the wood of your stairs will remain visible. Homebuilding’s handy guide to reviving wood floors can help you ensure it’s shown off to its best.

Measuring a Riser

staircase riser

Your next step is to measure a riser on your staircase. The riser is the vertical part of each step. You need to measure the height and the width of the riser.

The width ought to be the same as that of the tread, but it never hurts to double check. Note down your exact measurements and then round each one up. Make a note of the rounded figures too.

Measuring Landings

measure landings for carpet

If your staircase has a small landing part-way up, your carpet will need to cover this too. Take accurate measurements of the width and depth of the landing.

Note these figures on your piece of paper and also include the same rounded up measurements as before. Multiply the width of the landing by the depth to find its total area. Do this with both the exact and rounded figures.

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Pro Tip: Don’t forget that a landing will have a riser beneath it, just like any other step on your stairs. Make sure to include the height of that riser in your measurement of the landing’s depth.

Calculating Area

You now have all the measurements you need to calculate the total area which your stair carpet needs to cover. 

First, you need to add your measurement for the depth of a tread to that of the height of a riser. Then, multiply that figure by the width of the tread and riser (which should be the same).

You’ve now got the total area of one step. Multiply this by the number of steps on your stairs. Add that figure to the total area of any landing and write down the resulting figure. Repeat this process with your rounded-up measurements.

Repeat Steps Two-Five

You’ll now want to work through steps two to five in their entirety for a second time. Once you have, check all of your recorded measurements (exact and rounded) against your first set. You want each and every one to match.

This is the only foolproof way to discover if you made a mistake anywhere along the way. If all your figures match, you’re ready to move on. If they don’t, you’ll have to measure everything again to make sure you get it right.

Get Cutting and Fitting

fitting stair carper

Once you’re sure of your measurements, you can start cutting your carpet. It’s best to use your rounded-up figures and to then add around another 2.5cm for each step.

You’ll also want to add approximately 50cm to the total area, if you’re going to use underlay. That way, you’ll have a little slack to account for any mistakes whilst fitting the carpet.

Fitting is your next step, and will be much easier now you know you’ve got the right amount of carpet. If you need a little extra help, though, this guide to using carpet grippers from DIY-tips is a good place to start.


Final Thoughts

Our simple guide on how to measure stair carpet might not have put you on a stairway to heaven, but it should have made you more confident about livening up your stairs without having to call in a professional.

If you have any questions, or want to share your own experiences, please leave a comment below.

About the Author Neil Cumins

I’ve been a property journalist since 2003, writing about everything from architecture and construction to interior design and home improvements, for property clients all over the world

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