Area Converter
Convert between square metres, square kilometres, acres, hectares, square feet, square miles, square inches, square yards, and more — all area units instantly.
All Unit ConvertersAll conversions from 1 square metre
| Unit | Symbol | System | Value |
|---|
How the area converter handles 22 units, from barns to the surface of the Earth
Area is length squared, which sounds simple until the unit list grows to include square rods, decares, sections and a nuclear physics unit called the barn. This converter normalizes every one of those to square meters internally, then scales out to whatever unit you actually need. It covers metric, imperial and US customary, historical land measures still used in deeds and cadastral surveys, and a couple of scientific outliers included because people genuinely search for them.
Everything happens client side with a static array of conversion factors and multiplication. No network request is made, so the number you enter and the result you get never leave your browser.
The conversion pipeline
1 × 4046.8564224 square meters, using the exact legal definition rather than a rounded figure.
Full unit table, factor relative to one square metre
| Unit | Symbol | Category | Factor (m²) |
|---|---|---|---|
| Square millimetre | mm² | Metric | 0.000001 |
| Square centimetre | cm² | Metric | 0.0001 |
| Square decimetre | dm² | Metric | 0.01 |
| Square metre | m² | Metric | 1 (base unit) |
| Are | a | Metric | 100 |
| Decare | daa | Metric | 1,000 |
| Hectare | ha | Metric | 10,000 |
| Square kilometre | km² | Metric | 1,000,000 |
| Square inch | in² | Imperial | 0.00064516 |
| Square foot | ft² | Imperial | 0.09290304 |
| Square yard | yd² | Imperial | 0.83612736 |
| Acre | ac | Imperial | 4,046.8564224 |
| Square mile | mi² | Imperial | 2,589,988.110336 |
| Square rod | rd² | Imperial | 25.2928526 |
| Square chain | ch² | Imperial | 404.68564224 |
| Section (US survey) | sec | Land | 2,589,988.110336 |
| Township (US survey) | twp | Land | 93,239,571.97 |
| Rood | ro | Land | 1,011.7141056 |
| Square nautical mile | nmi² | Other | 3,429,904 |
| Square foot (US survey) | ft²(sur) | Other | 0.0929034116 |
| Barn | b | Other | 1e-28 |
| Earth surface area | E⊕ | Other | 5.10072e14 |
Two ways the tool makes numbers legible
Category badges
Every row in the full table carries a colored tag: metric, imperial, land or other. It is a quick visual filter when you are scanning 22 rows for the one unit that matches what your source document actually uses.
Real world comparisons
Alongside the raw conversion, the tool measures your input against a football pitch at 7,140 m², a tennis court at 261 m², an Olympic pool at 1,250 m² and a sheet of A4 paper at 0.0623 m², so a number like 3,200 square feet becomes something you can actually picture.
Where these units come from
The section and township come straight from the US Public Land Survey System established in 1785, which divided the American frontier into a grid of one-mile-square sections, 36 to a township. The chain and rod predate that by centuries, going back to English surveying practice where a Gunter’s chain of 66 feet made acreage calculations easy with whole numbers. The barn is the odd one out: physicists at Purdue and Cornell coined it during World War II atomic research because a nucleus’s cross sectional area of that size was, in their words, as big as a barn door compared to the scale they were working at.
Area unit references
- BIPM SI Brochure defines the square metre as the coherent derived unit for area.
- NOAA National Geodetic Survey documents the retirement of the US survey foot and its downstream effect on survey units like the acre and section.
- Schlumberger Oilfield Glossary and land survey references cover the rod, chain and township grid used in the Public Land Survey System.
- NIST Units and Systems of Measurement lists the barn among accepted non-SI units used in specialized fields.
Land and surface measurement in practice
Real estate listings that quote square footage but need converting to square metres for an international buyer, farmers comparing hectares against acres on adjoining plots, land surveyors reconciling an old deed written in rods and chains against a modern GPS survey, students converting textbook physics cross sections in barns, and homeowners figuring out how many rolls of turf or bags of mulch a garden bed actually needs once the area is expressed in the right unit.
Common Questions
FAQ: Area Converter
One acre equals exactly 43,560 square feet. It is also equal to 4840 square yards, 10 square chains, or approximately 4046.86 square metres. An acre is roughly the size of an American football field (without the end zones).
One hectare equals 2.47105 acres. Equivalently, one acre equals 0.404686 hectares. The hectare is the standard land measurement unit in most of the world outside the US. 100 hectares equals 1 square kilometre.
Multiply square metres by 10.7639 to get square feet. Or divide by 0.0929. One square metre equals approximately 10.76 square feet. For a quick mental estimate: multiply by 10 and add 7.6% for a rough number.
An are (a) equals 100 square metres — a 10 m × 10 m square. A decare (daa) equals 1000 square metres, or 10 ares. A hectare is 100 ares. The are and decare are used in some European and Turkish land registration systems, though hectares are more common globally.
A US survey section is a land parcel of exactly 1 square mile (640 acres). 36 sections make up a township (6 miles × 6 miles). This grid system was established by the Land Ordinance of 1785 and is how most US land in the Midwest and West was originally divided and sold.
One square mile equals 2.589988 km². One square kilometre equals 0.386102 square miles. So a square kilometre is about 38.6% the size of a square mile. Country areas in Europe are typically reported in km²; in the US, often in square miles.
From the blog
Reading around units
Where measurement systems came from and why two of them still argue.
