Free Area Unit Converter (m², Tsubo, Tatami Mats, Acres & More)
Free area unit converter. Convert m², cm², km², tsubo (坪), tatami mats (畳), ares (a), hectares (ha), acres, ft², yd², and mi² — into every unit at once from a single value, including traditional Japanese real-estate units.
Area conversion base values (1 unit = how many square meters)
| Unit | Base value |
|---|---|
| Square meter (m²) | 1 m2 = 1 m² |
| Square centimeter (cm²) | 1 cm2 = 0.0001 m² |
| Square kilometer (km²) | 1 km2 = 1,000,000 m² |
| Tsubo (坪) | 1 tsubo = 3.305785 m² |
| Tatami mat (畳, Edo-ma standard) | 1 jou = 1.6562 m² |
| Are (a) | 1 a = 100 m² |
| Hectare (ha) | 1 ha = 10,000 m² |
| Acre | 1 acre = 4,046.8564224 m² |
| Square foot (ft²) | 1 ft2 = 0.09290304 m² |
| Square yard (yd²) | 1 yd2 = 0.83612736 m² |
| Square mile (mi²) | 1 mi2 = 2,589,988.110336 m² |
What is an area unit converter?
Area units vary wildly by country and industry — real estate uses tsubo and tatami mats, farmland and parks use ares and hectares, and overseas listings often quote acres or square feet. This tool takes a single value and unit and instantly displays the converted result in all 11 supported units — m², cm², km², tsubo, tatami mats, a, ha, acre, ft², yd², and mi² — at once.
For units with regional variation, like the tatami mat, this tool calculates using the most widely used Edo-ma standard (1 jou = 1.6562 m²). Regions using other mat sizes, such as Kyo-ma or Danchi-ma, will see a real-world difference, so when precision matters it's worth checking the m² figure listed alongside a property's mat count as well.
How to use the area unit converter
- Choose the unit you're starting from Pick the unit your figure is currently expressed in — m², tsubo, acre, and so on — from the dropdown.
- Enter the value Type the area figure you want to convert into the input field.
- Check the full conversion table As soon as you enter a value, the converted result for all ten remaining units appears in a single list.
Tips for getting more out of it
- Enter one value and pick its unit, and all 11 area units — m², tsubo, tatami mats, acres, and more — are converted at the same time, so there's no need to look each one up separately.
- Tsubo and tatami mats (jou) are traditional Japanese units still used in real-estate and construction listings today, handy for comparing a property's size against other units.
- Tatami mat size varies by region — Edo-ma, Kyo-ma, and Danchi-ma standards all differ. This tool uses the most common Edo-ma standard (1 jou = 1.6562 m²).
- Acres and square feet, commonly used in overseas real-estate listings, are converted too — handy when comparing property sizes abroad.
Ways people use the area unit converter
Comparing tsubo or tatami listings in square meters
Convert the tsubo or mat count quoted in a rental listing into square meters so you can compare it fairly against other properties.
Making sense of overseas property listings
Convert acre or square-foot figures from listings abroad into the square meters or tsubo you're used to, to get a real feel for the size.
Understanding farmland or park sizes in hectares
Convert large plots quoted in ares or hectares into square meters or tsubo, so the scale becomes easier to picture.
Estimating materials for a DIY or renovation project
Use the square-meter conversion of a room's mat count as a rough guide when calculating how much flooring or wallpaper you'll need.
Area unit glossary
- Tsubo
- A traditional Japanese area unit rooted in the shakkanho system: the area of a square with 6-shaku (about 1.818 m) sides, equal to about 3.305785 m².
- Tatami mat (Edo-ma)
- The mat-size standard most common in the Kanto region: 1 jou = 1.6562 m², the standard this tool uses for its conversions.
- Are / hectare
- An are is a 10 m × 10 m square (100 m²); a hectare is 100 times larger (10,000 m²). Both are used across Europe to describe farmland and park sizes.
- Acre
- An area unit that originated in England, equal to about 4,047 m². Widely used across English-speaking countries to describe farms and other large plots of land.
- Shakkanho
- Japan's traditional system of weights and measures, the origin of many length and area units still in use, including the tsubo, the tatami mat, and the ken.
Frequently Asked Questions
Side Note — The history behind tsubo, tatami mats, and the acre
The tsubo comes from Japan's traditional shakkanho system of measurement. It is defined as the area of a square with sides of 6 shaku (about 1.818 meters), which works out to exactly the area of two tatami mats. Even after the metric system was introduced during the Meiji era, the tsubo remained deeply entrenched as the unit for describing land area, and Japanese real-estate ads and homebuilder catalogs still commonly quote a "price per tsubo" today.
The size of a single tatami mat is not standardized nationwide. Edo-ma (about 1.6562 m²), common in the Kanto region, Kyo-ma (about 1.824 m²), common in the Kansai region, and Danchi-ma (about 1.445 m²), common in apartment blocks, can differ substantially depending on the region and construction method. A room labeled "6 tatami mats" can therefore vary in actual size by nearly 50% between properties, so when apartment-hunting it is safer to check the floor area in square meters as well as the mat count.
The acre originated in medieval England, said to be based on the area of farmland a team of oxen could plow in a single day with a wooden plow. Today it remains in everyday use across English-speaking countries — the US, UK, and Canada — for describing large tracts of land such as farms, ranches, and golf courses. One acre is about 4,047 square meters, roughly a third of the playing field at the Tokyo Dome (about 1.3 hectares).