What is this converter?
Converts area between metric units (square millimetre to square kilometre), imperial units (square inch, square foot), and land-measurement units (acre, hectare). All conversions pass through the square metre.
Use it when:
- A property listing quotes land in acres or hectares and you think in square metres.
- You are converting floor area between square feet and square metres.
- You need consistent units for a material or costing estimate.
Intended for: Property buyers, builders, farmers, and anyone estimating material for a surface.
How is this calculated?
- Each supported unit is defined by a fixed conversion factor relative to one base unit for the quantity (for example, the metre for length).
- The value you enter is first converted from the source unit into that base unit by multiplying by the source unit's factor.
- The base value is then converted into the target unit by dividing by the target unit's factor.
- Because both factors are exact constants, the conversion is a single deterministic multiplication and division — the same input always produces the same output.
Example
Converting 1 acre to square metres.
- 1 acre is defined as 4,840 square yards.
- 1 square yard is 0.83612736 square metres.
- 4,840 × 0.83612736 ≈ 4,046.86.
Result: 1 acre ≈ 4,046.86 square metres, or about 0.4047 hectares.
Frequently asked questions
How many square feet are in a square metre?
About 10.7639. Note that this is the square of the linear ratio: a metre is about 3.2808 feet, and 3.2808² ≈ 10.7639. Area ratios are always the square of length ratios.
How do acres and hectares relate?
A hectare is 10,000 square metres and an acre is about 4,046.86, so one hectare is roughly 2.471 acres.
Assumptions
What this converter takes as given:
- Conversion factors are the internationally standardised definitions of each unit, not regional or historical variants.
- The value you enter is treated as an exact quantity — no measurement uncertainty is carried through the conversion.
- Results are rounded only for display; the underlying arithmetic uses full precision.
Limitations
What this converter cannot know or does not model:
- The converter does not know the precision of your original measurement, so it cannot report significant figures for you.
- Units that share a name but differ by region or era (for example, different definitions of a gallon or a ton) are offered only in the variants listed in the unit menu.
- Very large or very small magnitudes are subject to the limits of double-precision floating-point arithmetic.