Flooring Calculator
Enter your room measurements to get the flooring area you need, with a waste allowance for cuts. Flooring is sold per square metre (packed in boxes), so we also show the box maths if you know your pack size.
Enter your measurements
Your m² of flooring result will appear here instantly.
How to use this calculator
- 1
Measure the room's length and width at the widest points, in metres or centimetres.
- 2
For L-shaped rooms, split the space into two rectangles and add the two results together.
- 3
Keep the waste allowance at 10% for a straightforward straight lay, or raise it to 15% for diagonal patterns and rooms with lots of alcoves.
- 4
If you know the pack size printed on the box, enter it to get the number of packs to buy.
- 5
Acclimatise floating floors in the room for 48 hours before laying, and keep a spare pack for future repairs.
How the calculation works
Room area
Length × width gives the floor area in square metres. Measure at the widest points — skirting boards and uneven walls are why the waste allowance exists.
Waste allowance
Every row of boards ends in a cut, and every board you cut off short of a full use is waste. Straight layouts typically lose 5–10%; diagonal and herringbone patterns lose 15% or more.
Packs
Flooring is sold in boxes covering a stated area (often around 2–2.5 m²). We divide your total area by the pack size and round up — part packs cannot be bought.
Worked example
A living room 5 m × 4 m with 10% waste and 2.2 m² packs.
Room area = 20 m². With waste: 20 × 1.1 = 22 m².
22 ÷ 2.2 = 10 packs exactly.
Buy 22 m² — exactly 10 packs at 2.2 m² per pack. One spare pack for future repairs is a smart addition.
Frequently asked questions
How much extra flooring should I buy?
10% is the standard allowance for straight layouts in rectangular rooms; 15% for diagonal or herringbone patterns, irregular rooms, or boards laid across awkward angles. Flooring manufacturers won't honour claims for over-order, but running one board short mid-job is far worse.
Do skirting boards or wardrobes change the calculation?
Floating floors are usually laid under wardrobe carcasses but stop at skirting boards, with the gap hidden by the scotia or beading. If you are fitting flooring around built-ins, measure the floor they occupy and subtract it from the room area.
Can I use this for carpet?
Yes for a rough area estimate, but carpet is sold by the lineal metre off a roll (commonly 3.66 m or 4 m wide). Your carpet layer will plan the layout across the roll width — use this calculator for budgeting, and get a measure-and-quote for the actual order.
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Results are estimates only. Always confirm material requirements with your supplier or a qualified professional before purchasing.