How do I work out how many square metres a room is?

Measure the length and the width at the widest points, round each up to the nearest 10 cm, and multiply them together. A 4 m by 3.5 m room is 14 m².

Should I add extra for waste when measuring for flooring?

Yes. Add roughly 10% for a simple room, and more for patterned carpet, diagonal or herringbone LVT, or awkward shapes. Carpet also comes in fixed 4 m and 5 m roll widths, so part of the offcut is unavoidable.

How do you measure stairs for carpet?

Stairs are counted, not measured by area — treads, risers, winders and the landing. They are quoted as a package because the price reflects the fitting time rather than the square metres.

How to measure a room for flooring

Measuring your own room is useful for budgeting, and it takes five minutes. It is not a substitute for a fitter's measure — we do that free — but it will tell you roughly what you are spending before anyone comes out.

What you need

A tape measure, a phone to write numbers down, and a rough sketch of the room. Metres are easiest, because flooring in the UK is priced per square metre.

Step by step

For a normal rectangular room:

Measure the longest length wall to wall, at the widest point.
Measure the widest width the same way, including any doorway recess.
Round both up to the nearest 10 cm — always up, never down.
Multiply length by width for your square metres. A 4.2 m by 3.4 m bedroom is about 14.3 m².
Multiply that figure by the per-square-metre price for a rough cost.

Awkward shapes, bays and L-shapes

Split the room into rectangles, measure each one, then add them together. For a bay window, measure it as a separate rectangle at its deepest point. Always measure to the widest point of the whole room, because carpet and LVT come off a roll or in packs and the widest point is what determines how much has to be bought.

Why the fitter's figure is higher than yours

Two reasons. Waste: carpet comes in fixed roll widths, usually 4 m or 5 m, so a 3.2 m wide room still needs a 4 m width and the offcut is paid for. Pattern and plank direction: patterned carpet has to be matched, and LVT planks have to run the same way through a doorway to look right.

That is why a good measure includes doorways, thresholds and how the flooring will run from room to room, not just the floor area.

Stairs

Do not try to work stairs out per square metre. Count the treads and risers and any winders or turns, and let a fitter price it as a package — the labour, not the area, is what the price is made of. Small hallways and landings work the same way.

Want us to do it?

We measure free anywhere in Northamptonshire and put a fixed, itemised price in writing before anything is ordered, so there are no surprises once we are on site.

Quick answers

How do I work out how many square metres a room is?: Measure the length and the width at the widest points, round each up to the nearest 10 cm, and multiply them together. A 4 m by 3.5 m room is 14 m².
Should I add extra for waste when measuring for flooring?: Yes. Add roughly 10% for a simple room, and more for patterned carpet, diagonal or herringbone LVT, or awkward shapes. Carpet also comes in fixed 4 m and 5 m roll widths, so part of the offcut is unavoidable.
How do you measure stairs for carpet?: Stairs are counted, not measured by area — treads, risers, winders and the landing. They are quoted as a package because the price reflects the fitting time rather than the square metres.

Want a straight answer for your own room? Call 07342 203294 or see our flooring prices and areas we cover.