Area converter — square feet, square metres, acres and hectares

How to use the area converter

1. Put the area in Value, such as a floor plan figure or a plot size.
2. Choose its unit in From: square feet, square metres, acres, hectares and so on.
3. Choose the target unit in To and read the answer.
4. Check the table for every other unit at once, which is handy when a document mixes acres and hectares.
5. Use the swap button to convert back.

What it does and when to use it

This tool converts surface area across 11 units: square kilometres, hectares, ares, square metres, square centimetres and square millimetres on the metric side; square miles, acres, square yards, square feet and square inches on the imperial side.

Common reasons to use it are comparing property listings that quote square feet with ones that quote square metres, checking the size of a plot of land, ordering flooring, turf or paint by coverage, and converting farm or forest areas between acres and hectares. When you plan materials, the area is often only the first step; the volume converter takes over for concrete, soil or water by the cubic metre, and the weight converter helps when sand or gravel is sold by the tonne.

How it works: the factor is squared

Each unit is stored as a number of square metres. The imperial ones come from the exact inch (2.54 cm), so a square inch is 0.00064516 m² and a square foot is 0.09290304 m². An acre is defined as 4,840 square yards.

The common mistake is to use a length factor for an area. A metre is about 3.28 feet, but a square metre is about 10.76 square feet, because the ratio applies to both sides of the square: 3.28084 × 3.28084 ≈ 10.7639. If a result looks about three times too small, a length factor was probably used by mistake.

Worked examples

These figures are computed by the converter.

An apartment. 1,500 sq ft = 139.35456 m². That is 1,500 × 0.09290304, an exact result.

Farmland. 1 hectare = 2.47105381467 acres. A 40-hectare farm is therefore about 98.8 acres.

A square mile. 640 acres = 1 square mile, exactly. This is why US land is often divided into “sections” of 640 acres.

Limits and tips

• Shapes are not handled here. Work out the area first (length × width for a rectangle, half base × height for a triangle), then convert.
• Local land units such as the bigha, guntha, cent or tsubo are not included, because their size varies by region. Convert them to square metres using the local definition first.
• Measure once, in one unit. Converting each side and then multiplying can add rounding; multiply first, then convert.
• If you also need lengths for a floor plan, the length converter uses the same exact inch.