Sq Ft to Sq M Calculator

Background.

A square foot is a little less than a tenth of a square metre: 0.09290304 m², and that figure is exact rather than measured. Since the 1959 international yard-and-pound agreement the foot has been defined as precisely 0.3048 metres, and squaring a defined length gives a defined area, 0.3048 × 0.3048 = 0.09290304, with no digits trailing off behind it.

So converting is one multiplication. A 1,200 ft² floor, a typical figure on a US flooring quote, is 111.483648 m², which the converter shows as 111.4836. Whatever uncertainty the answer carries comes from the tape measure, never from the factor.

The errors that do creep in come from shortcuts. Multiplying by 0.0929 is close enough for almost anything, but dividing by 10.76, a common rounding of the reverse factor, turns the same 1,200 ft² into 111.5242 m², about 0.04 m² too much. Converting a room's sides to metres and rounding each one before multiplying drifts in the same way. Neither matters for a rug; both can matter when a supplier sells imported tile or engineered flooring by the square metre and every box counts.

What is sq ft to sq m calculator?

A square foot is the area of a square one foot on each side; a square metre is the SI unit of area, a square one metre on each side. Because the international foot is defined as exactly 0.3048 m, the area factor is the square of that number, 0.09290304 m² per ft², and the reverse factor is 1 ÷ 0.09290304, roughly 10.7639 ft² per m². Converting area never involves a measured physical constant, only these two definitions.

How to use this calculator.

1. 01Enter the area in square feet. If you only have a room's length and width in feet, multiply them first: a 12 ft by 15 ft room is 180 ft².
2. 02For an L-shaped or irregular floor, split it into rectangles, add their square footage, and enter the total.
3. 03Read the area in square metres. Add any waste allowance for cutting and breakage to this figure, then round up to whole boxes or packs at the supplier's coverage per box.

The formula.

m² = ft² × 0.09290304. The factor is 0.3048², the square of the number of metres in one international foot, so it carries no rounding at all. The conversion is linear: double the square footage and the square metres double, and there is no offset to worry about as there is with temperature. Converting dimensions first gives the same result, because (L × 0.3048) × (W × 0.3048) = L × W × 0.09290304; it only goes wrong when the intermediate lengths are rounded. A 12 by 15 ft room is 3.6576 m by 4.572 m, which multiplies to 16.7225472 m², exactly what 180 ft² × 0.09290304 gives, whereas rounding the sides to 3.66 m and 4.57 m first yields 16.7262 m².

A worked example.

Frequently asked questions.

References& sources.

1. [1]National Institute of Standards and Technology. SI Units — Length — the international foot is exactly 0.3048 meters, fixed by the 1959 international yard-and-pound agreement.
2. [2]National Institute of Standards and Technology (2008). NIST Special Publication 811: Guide for the Use of the International System of Units (SI), Appendix B — Conversion Factors.