Measure twice, cry once. Let’s carpet some rooms

Got bare floors mocking you every morning? Whether you’re carpeting a shoebox flat or a 21 room Victorian mansion, this calculator will tell you roughly how much carpet you need and how skint you’re about to be.

How to use the carpet calculator

This calculator works out carpet quantities and costs for multiple rooms, taking into account roll widths and wastage.

Room dimensions

Add as many rooms as you need using the “Add Another Room” button. Enter length and width in metres for each room. The calculator doesn’t judge if your spare room is actually just a glorified storage cupboard.

Draw a diagram

Create a simple sketch of the room to help visualise the measurements.

Measure length and width

Use a tape measure to find the longest and widest points of the room, including alcoves, recesses, and doorways. Measure twice because getting it wrong means either running short or having expensive leftovers.

Carpet details

Choose your carpet roll width (4m or 5m are standard). Enter the cost per square metre and set a wastage percentage – the default is 10% but 5-7% is more realistic for straightforward rooms.

You might want the full 10% if you’ve got awkward shapes or are worried about cutting mistakes.

Underlay

Don’t forget underlay costs – everyone does initially. Enter the price per square metre and the calculator includes this in your total, because apparently floors need cushioning too.

The calculation

The calculator works out how many carpet strips you need based on roll width, multiplies by the length needed, adds your wastage percentage, then calculates both the total carpet required and the costs for carpet and underlay.

It’s doing the tedious maths so you don’t have to

Results show your total room area, carpet required, and a breakdown of all costs. At least you’ll know what you’re dealing with before you start.

Use the remove buttons (×) to delete rooms you don’t need. All calculations update automatically as you change values.