You'll need about
20
m²
215.3
sq ft
23.9
square yards
Measuring up a job? Turn the area into a priced estimate. Build a free estimate.
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How this is calculated
length × width = area. Measure in metres and the answer is in square metres; a room 4.2 m by 3.6 m is 15.12 m². For an L-shaped space, split it into rectangles, work each one out and add them together.
This is a planning estimate — always confirm against your supplier and the specifics of the job before ordering.
Square metre calculator: FAQ
How do you calculate square metres?
Multiply length by width with both measurements in metres. A room 4.2 m long and 3.6 m wide is 4.2 × 3.6 = 15.12 m². If you measured in centimetres, divide each figure by 100 first — 420 cm × 360 cm is not 151,200 m².
How do I measure an awkward room?
Break it into rectangles, calculate each and add them up. For a bay or a curve, take the largest rectangle that contains it and accept the small over-measure — on a material order that over-measure is your waste allowance anyway.
How many square feet in a square metre?
About 10.76. It is not the 3.28 you might expect from metres to feet, because area scales with the square: 3.28 × 3.28 ≈ 10.76. This calculator shows both so you do not have to think about it.
Should I add waste?
Not to the measurement — measure the real area, then add waste when you order. Tiling and flooring usually take 10%, more for a diagonal or herringbone lay. Keeping the two numbers separate stops the waste allowance getting compounded twice.
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