How to Measure Carpet For Stairs in Four Easy Steps

Barn-style room with open staircase, sliding barn doors and brown carpet
Carpetright's Hoxton Carpet in Spice costs £42.99m2. (Image credit: Carpetright)

Knowing how to measure carpet for stairs is key to buying exactly how much you need. Measure up wrongly and you could be left with enough carpet to do the stairs three times over. 

Or worse, you underestimate how much carpet you need and are left three steps short. This could have a double whammy when you head back to the store — sold out, or the colour match is not quite the same.

In an ideal world your carpet needs to match with your stairs style. You might be renovating an old staircase or you're in need of some modern staircase ideas. Whatever stairs you have you still need to make sure that you are measuring up correctly for the carpet.

Here we give you a quick, simple, straightforward guide on how to work out how much carpet you are going to need to finish off your stairs.  

How To Measure Carpet For Stairs: Where to Start

Before you measuring carpet for stairs, you'll need to a few items to hand:

  • Pen/Pencil
  • Paper
  • Tape measure

This method for measuring carpet for stairs is for standard straight stairs with a landing at the top.

1. Draw out a plan
This is not an essential step in the process but it is a good idea to sketch out the area that you want carpeted as a reference point. You can mark down your measurements and then double and triple check that they are right. When finished you can make your calculations on the paper. It’s easier than trying to remember them in your head.

2. Measure the landing
At the top of your stairs you will have a landing area that continues on from your top step. Typically this will be a small area the same width as the stairs. Simply measure the width and depth/length of the landing and mark down on your sketch. This gives the area for the landing, e.g 1m x 1m = 1m/2

3. Measure the stairs
Kick off by counting how many steps you have on your stairs. Now choose a step to measure – try one in the middle or near the bottom – and measure the tread (the flat bit you step on) from the back and over the edge of the step to the riser (the upright bit). Now measure the riser and add together to get the whole step length. 

Also measure the width of the step and note down on your plan.

4. Get the final result
Take the length of the tread and riser and multiply by the width of the stair to get the area for a single step, e.g: 0.45m x 0.75m= 0.33/m2. 

Now multiply this by the number of stairs i.e.: 11 x 0.33m = 3.63m/2. 

Finally add in the landing area i.e. 0.82m x 0.88m = 0.72m/2 to get the final total. 

In this example it is 4.35/m2. Round this up to 5/m2 to ensure you have enough carpet. (Always add on a minimum of 10% to account for wastage.)

How to measure stairs for carpet illustration

(Image credit: Future/Steve Jenkins)

How To Measure Carpet For Half Landings 

This is a very similar process to measuring a standard landing. Measure from the back of the landing adjacent to the top step – on the stairs going down – to the bottom of the riser and then the width and multiply together.

This will help ensure that the carpet will fit over the landing and top step with one piece of carpet making it harder to spot any joins.

If you do any painting after the carpet has been laid make sure you prep properly so not to get paint on the carpet. However, if you do, don't panic, it's simply a matter of knowing how to get paint off carpet. And the quicker you do it the easier it will be. 

Measuring Carpet For Stairs with Winders 

If your staircase design features a corner with irregular shaped steps (these are known as winders) then the measuring process is slightly different. 

For each winder – you will need to measure individually as they will be slightly different in size. First measure the riser and tread – should be similar to the rest of the stairs – and then along the widest part of the winder. Repeat for each winder and add together to get the final area.  

If the paintwork gets chipped or marked when being fitted you will need to repaint without getting paint on the carpet. This is a very similar process to painting skirting boards with carpet. You'll need some painter's tape and dust sheets. 

Steve Jenkins

Steve is Homebuilding & Renovating's DIY content editor, and has been a writer and editor for two decades. He is an avid DIYer with over 20 years of experience in transforming and renovating homes. He specialises in painting and decorating, but has strong all-round building skills, having previously worked in the industry for 10 years.