Area Converter
An area converter restates one area in every other unit at the same time. Type the number, pick the unit it is in, and all ten rows update instantly: 1 acre shows as 4046.86 m2, 43560.057 ft2, 4840.0064 yd2, 0.404686 ha and 0.0015625014 mi2. Nothing is submitted - the arithmetic runs in the page as you type.
Converted Values
About Area Converter
Every unit on this page is stored as a factor against the square metre, so a conversion is one multiplication and one division rather than a chain of steps that accumulates error. The ten units are square millimetres, square centimetres, square inches, square metres, square feet, square yards, acres, hectares, square kilometres and square miles. Enter a value, choose the unit in the From menu, and the result list beneath shows all ten at once with the source unit highlighted.
Two controls sit on each result row. The clipboard button copies just that number, so you can take 107639.15 ft2 out of a hectare without selecting text by hand. The swap arrow makes that row the new input: press it on the square feet row and the value moves into the box with the unit set to ft2. Six preset buttons load a familiar reference in one click - a 20 m2 room, one acre, a 7,140 m2 football pitch, one hectare, a 260.87 m2 tennis court and one square kilometre.
Results are shown to eight significant figures, and anything below 0.0001 or above 1,000,000 switches to scientific notation, which is why 1 mm2 reads 1.0000e-6 m2 and 1 acre reads 4.0469e+9 mm2. Metric-to-metric conversions here are exact because the factors are powers of ten: a hectare is 10,000 m2 and a square kilometre is 1,000,000 m2.
The imperial factors are rounded to six significant figures, which shows up in the last digits of the big relationships. NIST records that the 1959 international agreement made the inch exactly 25.4 mm, from which an acre is exactly 43,560 ft2 and a square mile exactly 640 acres. This page returns 43560.057 and 639.99943 instead. The error is under one part in a million - irrelevant for a room, a garden or a plot listing, and not good enough for a land registry document, where you should use the exact definitions.
Use Cases
How to use
Type the area you already have into the Value box; the list below recalculates on every keystroke, with no button to press.
Choose the unit that value is in from the From menu, which lists all ten units with both the name and the symbol.
Read the Converted values panel - your source unit is highlighted, and the other nine rows show the same area restated.
Press a preset button to load a reference area instead of typing: a 20 m2 room, one acre, a football pitch, one hectare, a tennis court or one square kilometre.
Use the clipboard button on a row to copy that single figure, or the swap arrow to move that row into the input box as the new source.
Pro Tips
- The swap arrow on a result row is a round trip, not a rename. Press it on the square feet row after entering 1 acre and the box fills with 43560.057, which converts back to 0.99999999 ac - the rounding is visible, so re-enter the round number rather than chaining swaps.
- Results below 0.0001 and above 1,000,000 are printed in scientific notation. 1.0000e-6 means 0.000001, and 4.0469e+9 means 4,046,900,000. Switch to a bigger or smaller source unit if you need the plain digits.
- The preset row is faster than typing for a sanity check: the 260.87 m2 tennis court is the doubles court at 78 by 36 feet, and the 7,140 m2 football pitch is a 105 by 68 metre field.
- Copy the individual row rather than the whole panel. Each result has its own clipboard button, which puts only that number on the clipboard - no unit, no label - so it pastes cleanly into a spreadsheet cell.
- For legal or registry work use the defined values rather than this page: an acre is exactly 43,560 square feet and a square mile is exactly 640 acres, while the rounded factors here return 43560.057 and 639.99943.
Troubleshooting
Converting an acre to square feet gives 43560.057 rather than exactly 43,560.
The square foot factor in this page is rounded to 0.092903 m2 instead of the exact 0.09290304 that follows from the 1959 definition of the inch as 25.4 mm. The error is about six parts in ten million. Round the answer yourself for a document, or use the defined figure of 43,560 square feet per acre where exactness matters.
A number comes back as 3.8610e-7 and is unreadable.
That is scientific notation, used automatically for results under 0.0001 or over 1,000,000. It means 0.00000038610. Pick a source unit nearer the size of the answer - entering the area in square kilometres rather than square metres, for instance - and the figure returns to plain digits.
The result rows are all zero.
The value box is empty or holds zero; a blank input is read as zero and every row is then zero, which is correct rather than broken. Type a number, or press one of the preset buttons to load a worked example such as one hectare.
Pressing the swap arrow repeatedly slowly changes the number.
The swap arrow copies the displayed, already-rounded result into the input box, so each pass loses a little precision: 1 acre becomes 43560.057 ft2, which converts back to 0.99999999 ac. Use swap once to change perspective, and retype the original round number rather than chaining several swaps.
The clipboard button does not appear to copy anything.
Copying uses the browser clipboard API, which needs a secure context and can be refused by browser settings or an extension. When it works, the tick replaces the clipboard icon for about a second and a half. If it never does, select the number with the mouse and copy it in the usual way - the value shown is the full result.
Frequently Asked Questions
A tool that takes one area and expresses it in other units. This one converts between ten at once - square millimetres, centimetres, inches, metres, feet, yards, acres, hectares, square kilometres and square miles - by holding every unit as a factor against the square metre, so the whole list updates from a single keystroke rather than one pair at a time.
Type the number into the value box, set the From menu to the unit you already have, and read the Square Meters row in the list underneath. Because square metres are the base unit here, that row is the number every other row is derived from: 1 acre gives 4046.86 m2, 1 hectare gives 10000 m2 and 1000 ft2 gives 92.903 m2.
Exactly 43,560 by definition, since an acre is 4,840 square yards and the 1959 international agreement fixes the inch at exactly 25.4 mm. This page shows 43560.057 because its square foot factor is rounded to 0.092903 rather than the exact 0.09290304. Use it for estimating and the defined figure for anything contractual.
A hectare is 10,000 square metres, and this converter returns 2.4710516 acres for it - the exact value is 2.4710538. Going the other way, 1 acre is 0.404686 hectares. The quick mental version is that a hectare is about two and a half acres, which is close enough to compare two plot listings at a glance.
Enter the figure, set From to Square Feet, and read the Square Meters row: 1000 ft2 comes back as 92.903 m2. The multiplier is 0.092903 m2 per square foot in this tool, against the exact 0.09290304. Going the other way, 1 m2 shows as 10.763915 ft2, so multiplying by roughly 10.76 is the mental shortcut.
They belong to different systems. The hectare is metric and defined as exactly 10,000 square metres, a square 100 metres on a side. The acre is an imperial unit defined as 4,840 square yards, which works out at 4046.86 m2 here. A hectare is therefore about 2.47 acres, and a square kilometre - 100 hectares - is 247.10516 acres in this converter.
The result list switches to scientific notation when a value falls below 0.0001 or rises above 1,000,000, because eight significant figures of a very small or very large number would otherwise be unreadable. 1.0000e-6 is 0.000001 and 4.0469e+9 is 4,046,900,000. Choosing a source unit closer in size to the answer keeps the numbers in plain form.
No, and no converter can. A perimeter does not determine an area - a 40-metre perimeter can enclose a 100 m2 square or a 75 m2 rectangle. This page only restates an area you already know in another unit. Work out the area first from the shape, then bring the number here.
No. The list is limited to the ten metric and imperial units in the results panel. Regional land units vary by state and even by district, so a single fixed factor would be wrong for most readers. Convert your local unit to square metres using your own regional definition first, then use this page for the rest.
Metric to metric is exact, because those factors are powers of ten. The imperial factors are rounded to six significant figures, so relationships that should be exact drift in the last digits: an acre reads 43560.057 ft2 instead of 43,560 and a square mile reads 639.99943 acres instead of 640. That is better than one part in a million, which is fine for building work and wrong for a legal description.