How to Measure for Carpet

To save yourself from overspending on labor or materials, it’s a good idea to find out exactly how much carpet you need. Your retailer or carpet fitter will ask for the right measurements before making an order. Here is a basic guide on how to work out carpet size in all rooms, including the stairs. This will give you an estimate of the amount of carpet and underlay required.

To start, it’s easier if you draw a diagram of the room where the carpet is going. It should be a basic bird’s eye view of the floor plan, including walls and doors. It doesn’t need to be exactly to scale, as you will then simply annotate the accurate measurements.

Measuring a room for carpet

Let’s start with the simple part, measuring the room. You’ll first need to take the following measurements with a tape measure.

Width (1) x Length (2)

Measure the maximum width and length at the room’s widest points. Label the width as 1 and the length as 2.

Measure indentations (3, 4)

Examples of indentations could be bay windows or chimney alcoves. For one fireplace indentation, for example, label the length 3 and the width 4. Label all other indentations separately, so you can calculate their area in square meters/feet by multiplying the length by the width. This can then be deducted from the overall area.

Measure the door frame (5)

Don’t forget to consider the space under the door protruding out of the room. You’ll need a little extra carpet here as well.

In order to calculate an estimation of how much carpet you will need, you need to multiply the main width (1) by the main length (2). This will give you the area in square meters (or feet) depending on which measuring system your carpet fitter uses. See example:

3m (1) x 5m (2) = 15㎡

You can then subtract the area of the indentations, and don’t forget to add on the space under the door.

0.5m (3) x 2m (4) = 1㎡
15㎡ - 1㎡ = 14㎡
14㎡ + (5)

Your carpet supplier will provide you with the price per square meter, so you can calculate the total cost for the room. Always round up your measurements and the price, as your carpet fitter will most likely do.

Measuring stairs for carpet

Measuring your stairs isn’t as complicated as it may sound. Your stairs should all be the same size, so you’ll only need to measure one of them to know how to work out carpet size. Here is the easy way to work out measurements. There are three measurements you need to make when you’re measuring stairs for carpet.

Measure tread (1)

The tread is the depth of the step. Be generous with the tape measure to take into account the bend of the edge of the step. Label the tread measurement as 1.

Measure rise (2)

The rise is the height of an individual step. Label the rise measurement as 2. Add 1 and 2 together, and you will have the length of the carpet you need for one step. Count your steps and multiply by the first number like this:

20cm (1) + 20cm (2) = 40cm
no. of steps 10
10 x 40cm = 4m

This is the total length of carpet required.

Measure width (3)

Measure the width of one step and add on 5cm for the edge again. Label the width 3. You can now multiply this by the overall length you calculated before to work out the carpet area.

4m x 1.5m (3) = 6㎡

Here is the estimated area for your stairs. It’s a good idea to add 5cm approx. to your measurements to account for edges and underlay. You carpet retailer will be able to give the price per meter, so you can calculate the overall cost for your carpet.

Extra tips

• If you’re ordering patterned carpets, you might want to think about ordering extra to line them up. Imagine you have a repeating motif, for example, you’ll want this to be symmetrical and consistent.
• Winding spiral staircases will need more carpet to compensate for the change in pile direction. A professional fitter will help you get a more accurate carpet measurement.
• Always compensate for underlay. Speak to your carpet retailer about how much they advise adding on.
  Remember, these are just basic guidelines. You’ll need an expert carpet fitter to ensure your measurements are precise. They’ll most likely take the carpet measurement of the room themselves.