About Area Converter
Area Converter translates a surface measurement between eight units: square millimetres, square centimetres, square metres, square kilometres, hectares, acres, square feet and square inches. It is the tool for switching between the metric land measures and the imperial ones — an acre of farmland to square metres, a floor plan in square feet to square metres.
The relationships follow from the length definitions squared, so an acre works out to 4046.86 square metres and a hectare to exactly 10000. That makes the hectare a tidy 100 metres by 100 metres, while the acre, being a historical unit, carries the awkward figure it always has. Square units scale with the square of their linear counterparts, which is why a square kilometre holds a million square metres rather than a thousand.
The result comes back as a plain number with no unit suffix, the unit being whatever you selected in the second dropdown. Because areas grow quickly, results can span many orders of magnitude — a hectare in square millimetres is a ten-digit figure — so read the magnitude before pasting a value into anything important.
How to use Area Converter
- 1 Type the area measurement into the value field.
- 2 Select the square unit the measurement is expressed in.
- 3 Select the square unit you want, then run the conversion.
Frequently asked questions
Why is a hectare exactly 10000 square metres?
Because the hectare was defined as the area of a square 100 metres on each side. That makes it a neat metric unit, unlike the acre, which descends from historical ploughing measures and equals about 4046.86 square metres.
How many square feet are in a square metre?
About 10.764. Since a metre is 3.28084 feet, a square metre is that figure squared, which is just over ten square feet. The tool does the squaring for you through the stored factors.
Are acres the international or US version?
The tool uses the international acre of 4046.86 square metres, which is the standard in both the US and the UK. Historical regional acres are not offered, and they differ enough that a result based on one would not match this output.
Why does the number have so many digits?
Because area ratios between large and small units are big numbers. A square kilometre in square millimetres is a twelve-digit figure. The result is rounded to eight decimal places, so round the magnitude yourself for display.
Free, online, and private
Free to use
Area Converter is completely free. There is no account to create, no login, and no hidden charge or usage limit.
Runs online in your browser
It is a free online tool that runs entirely in your browser. Nothing to download or install — open the page and start using it right away.
Your data stays private
All processing happens locally on your device. Your input is never uploaded, stored, or tracked, so it never leaves your browser.
How Area Converter behaves in detail
These are the specifics of this implementation — the exact ranges, defaults and fixed settings you are working with.
| Parameter | Value |
|---|---|
| Units covered | 8 — mm², cm², m², km², hectares, acres, ft² and in² |
| Conversion basis | square metre — each of the eight units is a fixed multiple of it |
| Arithmetic applied | (value × from-unit factor) ÷ to-unit factor — one multiply and one divide, no rounding in between |
| Anchors | 1 km² = 1,000,000 m² · 1 ha = 10,000 m² · 1 acre = 4,046.86 m² · 1 ft² = 0.092903 m² · 1 in² = 0.00064516 m² |
| Result precision | 8 decimal places, from a starting Value of 1 |
| Default pair | m² → ft² |
Compiled from the implementation of this tool and checked against it by itoolnet.
What Area Converter does not do
Knowing the edges of a tool saves more time than another list of its features. These are the cases where it will not do what you might expect.
- The acre is hard-coded at 4,046.86 square metres, which is the international acre rounded to six significant figures. The exact value is 4,046.8564224 m², so anything routed through acres is already off in the fifth decimal place — and land recorded in US survey acres differs again.
- Results come back as one plain decimal number in the unit you chose. There is no compound land-survey output, so an area never reads as acres plus roods plus perches, and there is no round-to-significant-figures option for very large or very small plots.
- The non-metric side holds only three units — acres, ft² and in². Square yards, square miles, roods, dunams, barns and township sections are absent, so an imperial figure such as 2,560 square yards needs two passes through ft² before this converter can be used.
Tested and documented by itoolnet, the team that builds and maintains this site.