Use this area converter to change a known surface area between square feet, square meters, acres, hectares and other supported units.
Convert an area already measured
Enter the area you already know, select its unit in From, then choose the target unit in To. The main result gives that equivalent measurement; the common-equivalents list makes other supported units easy to compare.
The input is a surface-area total. A length alone cannot be converted into an area without another dimension.
Choose the unit stated with the original measurement. Historical survey-foot areas and regional land units are not interchangeable with these definitions.
Zero is accepted. Unsupported requested results are rejected; other equivalents outside the numeric range are labeled explicitly.
Area Converter example
- A room area already measured as 144 converts to 13.3780378 m².
- Select square feet in From and square meters in To; the shape and room dimensions are unnecessary because the area is already known.
Common area conversions
Each row expresses the same known area of 1 in a different supported unit.
| Area unit | Equivalent to 1 |
|---|---|
| Square foot | 10.7639104 |
| Square meter | 1 |
| Square yard | 1.19599005 |
| Square inch | 1,550.0031 |
| Square centimeter | 10,000 |
| Square millimeter | 1,000,000 |
| Square kilometer | 1e-6 |
| Square mile | 3.86102159e-7 |
| Acre (international foot) | 0.000247105381 |
| Hectare | 0.0001 |
| Are | 0.01 |
| Square decimeter | 100 |
Values are calculated with the declared unit factors and rounded to up to nine significant digits for display. Scientific notation keeps very small values visible. Acres and square miles use the international foot. These values are engine-derived from NIST’s revised international-foot factors, SP811 area definitions and SI-prefix definitions, listed in References.
Why area conversions use squared factors
Area conversion scales both dimensions. The NIST length and area definitions therefore use a squared length factor rather than the length factor itself. For example, 1 is 0.09290304 , and 144 is 1 .
The calculator applies the unrounded source-to-target area-factor ratio before multiplying, then rounds only the displayed answer. That order also avoids unnecessary intermediate overflow. A same-unit conversion keeps the entered numeric value. Positive inputs and requested results that fall outside the supported numeric range are rejected instead of returning a misleading zero.
When you have room or shape dimensions rather than an area total, Square Footage Calculator first measures the surface. A distance around the outside edge belongs in Perimeter Calculator; changing area units cannot determine that boundary length.
A converted area is a measurement, while an order also needs product-specific coverage or package information. Flooring Calculator, Tile Calculator and Paint Calculator use those additional inputs.
Choose the right land-area definition
The acre preset converts 1 to 43,560 . The same declared acre is 4,046.85642 m². A hectare is 10,000 m², and the hectare preset gives 2.47105381 acres.
These customary area units use the international foot. Older records may explicitly name the U.S. survey foot; its derived areas use a different factor. This converter excludes that legacy definition and regional units such as bigha, katha and arpent, whose meanings can depend on location. Keep the definition given in the original record rather than treating a similarly named unit as interchangeable. NIST’s revised conversion factors distinguish the international-foot factors used here.
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