Area Converter
Convert between square millimeters, centimeters, meters, kilometers, hectares, acres, square feet and more.
What is area and how is it measured?
Area is the measure of a two-dimensional surface — the amount of space enclosed within a boundary. It is always expressed in squared units (m², ft², km²) because it represents length multiplied by length. A room 5 m long and 4 m wide has an area of 20 m²; a square kilometre is 1,000 m × 1,000 m = 1,000,000 m².
All conversions on this page use square meters (m²) as the base unit — the SI standard for area. Every other unit is converted by first expressing it in m², then dividing by the target unit's m² equivalent.
The squared unit trap: why area conversions surprise people
The most common area conversion mistake is applying a linear conversion factor to a square measurement. Because area scales with the square of the linear unit, the conversion factor must be squared too.
Linear: 1 m = 100 cm → factor 100
Area: 1 m² = 10,000 cm² → factor 100² = 10,000
Linear: 1 ft = 0.3048 m → factor 0.3048
Area: 1 ft² = 0.092903 m² → factor 0.3048² ≈ 0.0929
Mistake: "1 m² = 100 cm²" ✗ (off by factor 100)
Correct: "1 m² = 10,000 cm²" ✓This scaling effect becomes even more dramatic at large scales. 1 km² = 1,000,000 m², not 1,000 m². A country's area in km² must be multiplied by one million to get m², and by 247.1 to get acres.
Hectares and acres: land measurement explained
For measuring land, the two most common non-SI units are the hectare (ha) and the acre. Both were designed to represent a practical, human-scale area — roughly the amount of land one farmer could work in a day.
| Unit | In m² | Equivalent | Primarily used |
|---|---|---|---|
| Hectare (ha) | 10,000 m² | 100 m × 100 m square | Europe, international agriculture |
| Acre | 4,046.86 m² | ≈ 0.405 ha | US, UK real estate & farming |
| km² | 1,000,000 m² | 100 hectares | Country/region sizes |
| mi² | 2,589,988 m² | 640 acres | US land surveys, county sizes |
One acre was originally defined as the area a yoke of oxen could plough in one day — a furlong (201 m) long and one chain (20 m) wide, giving 4,047 m². The hectare, introduced with the metric system, is a rounder 10,000 m², making it easier to use in calculations. One hectare is approximately 2.471 acres.
Common real-world uses
Worked conversion examples
A 1,500 ft² apartment in m²:
1,500 × 0.092903 = 139.35 m²
A 50-acre farm in hectares:
50 × 4046.856 ÷ 10,000 = 20.23 ha
The Netherlands (41,543 km²) in acres:
41,543 × 1,000,000 ÷ 4046.856 ≈ 10.26 million acres
A football pitch (105 × 68 m) in m²:
105 × 68 = 7,140 m² = 0.714 ha ≈ 1.76 acresTips for avoiding area conversion errors
- Always square the linear factor. If you know 1 inch = 2.54 cm, then 1 in² = 2.54² = 6.4516 cm². Never apply a linear conversion factor directly to an area measurement.
- Hectares are not the same as square kilometers. 1 km² = 100 ha, not 1 ha. When reading European property listings, a plot of "1 ha" is 10,000 m² — not 1 km².
- US real estate uses square feet, not yards. Even though yards are common for length in the US, floor area is almost always expressed in ft². A 2,000 ft² home is about 186 m² — roughly 222 yd² if you needed to know.
- Material coverage calculations compound errors. Buying tiles for a 15 ft × 12 ft room? Convert to m² first (180 ft² × 0.0929 = 16.7 m²), add 10% for cuts and waste, then order by m². Doing the conversion after adding waste introduces a different error.
Frequently asked questions
How many square feet are in a square meter?
One square meter equals about 10.764 square feet. To convert m² to ft², multiply by 10.764.
How big is an acre?
An acre is 43,560 square feet, or about 4,047 square meters — roughly the size of a standard football pitch without the end zones.
How many square meters are in a hectare?
One hectare equals 10,000 square meters, or about 2.47 acres. It is widely used for land and agriculture.
How do I calculate the area of a room?
Multiply length by width in the same unit. A 4 m × 5 m room is 20 m². Use this tool to then convert that figure to other units.
All areas convert through square meters (m²). Click any tile to use that value as new input.