Area Converter
Enter an area, choose your units, and watch the result update as you type. The table below shows the same area in all six units at once — nothing you enter ever leaves your browser.
Enter a number to see the conversion.
| Square meters (m²) | — |
|---|---|
| Square feet (ft²) | — |
| Acres | — |
| Hectares (ha) | — |
| Square kilometers (km²) | — |
| Square miles (mi²) | — |
Six area units, one exact set of conversion factors
Every conversion here runs through square meters as a common base, using conversion factors that are exact definitions rather than rounded approximations. 1 square foot is exactly 0.09290304 m², from the international foot fixed at exactly 0.3048 meters. 1 acre is exactly 4,046.8564224 m² — 43,560 square feet using that same exact foot. 1 hectare is exactly 10,000 m² and 1 square kilometer is exactly 1,000,000 m², both straight from the metric system's own definitions. 1 square mile is exactly 2,589,988.110336 m², from the international mile of 1,609.344 meters. Because every factor is exact, the only limit on precision here is floating-point arithmetic, not the constants themselves.
Worked example
1 acre equals 4,046.8564224 m², about 0.4047 hectares, and exactly 43,560 ft² — you can check that last one yourself: 43,560 × 0.09290304 ≈ 4,046.86 m², the same number either way. Going the other direction, 1 hectare is about 2.4711 acres, which is why a "2.5-acre lot" in US real-estate listings is almost exactly a 1-hectare plot in a European one.
Frequently asked questions
Why is an acre such an odd number of square meters?
Because it wasn't defined in metric terms to begin with — an acre traces back to the area a yoke of oxen could plow in a day, and was later standardized as 43,560 square feet (1 chain × 1 furlong, old English land-survey units). Converted through the international foot (exactly 0.3048 m), that works out to exactly 4,046.8564224 square meters — an odd-looking number in metric because the acre was never designed to be one.
What's the difference between a hectare and a square kilometer?
A hectare is 10,000 m² — a 100 m × 100 m square — the standard unit for land parcels, farms, and forests in most of the world. A square kilometer is 1,000,000 m², or exactly 100 hectares, and is used for larger areas like cities, districts, or countries. If a plot measures in the tens or hundreds, it's usually described in hectares; once you're talking about a whole region, km² takes over.
How precise are these conversions?
Every factor is an exact defined constant, not a rounded approximation. 1 square foot = 0.3048² = 0.09290304 m² exactly, from the international foot agreed in 1959. 1 acre = 4,046.8564224 m² exactly (43,560 sq ft using that same exact foot). 1 hectare = 10,000 m² and 1 km² = 1,000,000 m² are exact by the plain metric definitions. 1 square mile = 1,609.344² = 2,589,988.110336 m² exactly. Because every factor is exact, the only limit on precision is floating-point arithmetic, never the constants themselves.
Why do the US and most of the world measure land differently?
The US (and to a lesser extent the UK) kept acres as the standard land-measurement unit from British imperial surveying, and it's still what real-estate listings, farms, and zoning use in the US today. Most of the rest of the world — including the EU's land registries — switched to the metric hectare and square meter, which is why European property listings and agricultural statistics are given in hectares rather than acres.