How to Measure a Room for Flooring

Measuring a room for flooring is simple arithmetic, but two things trip people up: irregular shapes, and forgetting the wastage allowance. Get both right and you will order the correct amount once - which matters, because a second batch ordered later may not match the colour of the first.

What you need

A tape measure (a laser measure is faster for big rooms), a pen and paper, and a calculator. Work in whichever units your flooring is sold in - square feet or square metres - but it is fine to measure in feet/inches or metres; the flooring calculator converts for you.

Step 1: Measure a simple rectangular room

1. Measure the length of the room at floor level, along the skirting.
2. Measure the width the same way.
3. Multiply the two for the floor area.

A 5 m × 4 m room is 20 m²; a 16 ft × 13 ft room is 208 sq ft. Measure at floor level, not across furniture, and round measurements up to the nearest few centimetres or inches.

Step 2: Handle L-shaped and irregular rooms

Do not try to measure an odd shape in one go. Instead:

1. Split the floor into rectangles - draw the room and divide it into two or three boxes.
2. Measure and calculate each rectangle separately.
3. Add the areas together.

For a room with a chimney breast or a kitchen island the floor does not cover, measure those out as their own rectangle and subtract them.

Step 3: Include doorways and thresholds

Flooring runs into doorways and stops under the threshold strip, so the floor continues past the wall line. Measure to the centre of each doorway rather than to the door frame. It is a small amount, but it is real flooring you need to buy.

Step 4: Add the wastage allowance

Never order the bare floor area. You always lose some flooring to:

• the offcut at the end of each row (which often becomes the start of the next row, but not always),
• boards or tiles that crack during cutting, and
• a spare or two kept back for future repairs.

Layout	Add	Why
Straight, square room	5%	Cuts only at two walls
Diagonal or long room	10%	More angled and end cuts
Herringbone / chevron	15%	A cut at almost every board

Step 5: Convert area into boxes

Flooring is sold by the box, not the square metre, so the last step is dividing your total area (plus wastage) by the coverage printed on the box. That is fiddly to do by hand - the flooring calculator does it for you, including the wastage allowance, and tells you how many boxes to buy.

A worked example

A 5 m × 4 m living room, straight layout, laminate boxes that each cover 2 m²:

1. Area: 5 × 4 = 20 m².
2. Add 5% wastage: 20 × 1.05 = 21 m².
3. Boxes: 21 ÷ 2 = 10.5, rounded up to 11 boxes.

The one rule that saves projects

Buy it all at once, from the same batch, and check the batch (or “dye lot”) number matches on every box. Flooring shade varies between production runs, so a few boxes bought later to make up a shortfall can be visibly different across the floor. Measuring carefully up front is how you avoid that.