Acres Converter
Convert Acres (ac) to any other area unit. The table below gives the exact figure for each unit, and every conversion is worked from the same engine as the converter.
What acres convert to
One ac in every other area unit.
| Unit | 1 ac | Reverse |
|---|---|---|
| Square millimeters | 4,046,856,422.400001 mm² | 2.4711e-10 ac |
| Square centimeters | 40,468,564.224 cm² | 2.4711e-8 ac |
| Square meters | 4,046.856422 m² | 2.4711e-4 ac |
| Square kilometers | 0.004047 km² | 247.105381 ac |
| Hectares | 0.404686 ha | 2.471054 ac |
| Square feet | 43,560 ft² | 2.2957e-5 ac |
| Square inches | 6,272,640 in² | 1.5942e-7 ac |
| Square yards | 4,840 yd² | 2.0661e-4 ac |
| Square miles | 0.001563 mi² | 640 ac |
Multiply a acres figure by the figure in the second column to get the unit in the first, or multiply by the third column to go the other way.
Acres conversion reference
Acres to Square millimeters
One acres is 4,046,856,422.400001 square millimeters, and one square millimeters is 2.4711e-10 acres.
A square millimeter is one millionth of a square meter. It is used for small cross-sections, circuit boards and material specifications.
- 1 ac= 4,046,856,422.400001 mm²
- 5 ac= 20,234,282,112 mm²
- 10 ac= 40,468,564,224 mm²
Acres to Square centimeters
One acres is 40,468,564.224 square centimeters, and one square centimeters is 2.4711e-8 acres.
A square centimeter is one ten-thousandth of a square meter. It is used for small surfaces such as fabric swatches, skin areas and craft work.
- 1 ac= 40,468,564.224 cm²
- 5 ac= 202,342,821.12 cm²
- 10 ac= 404,685,642.24 cm²
Acres to Square meters
One acres is 4,046.856422 square meters, and one square meters is 2.4711e-4 acres.
The square meter is the SI unit of area. It is used for floor space, land plots and material quantities such as tiles or paint coverage; a parking bay is about 12 square meters.
- 1 ac= 4,046.856422 m²
- 5 ac= 20,234.282112 m²
- 10 ac= 40,468.564224 m²
The square meter is the International System unit of area, the area of a square with one-meter sides. It is the base for all metric area measures.
Apartment and office floor areas, building permits, land in urban plots, solar panel output per unit and fabric are measured in square meters in metric countries. Tiling and flooring quantities follow the same unit.
Acres to Square kilometers
One acres is 0.004047 square kilometers, and one square kilometers is 247.105381 acres.
A square kilometer is one million square meters. It is used for districts, national parks and country areas — and one square kilometer is exactly 100 hectares.
- 1 ac= 0.004047 km²
- 5 ac= 0.020234 km²
- 10 ac= 0.040469 km²
A square kilometer is the area of a square one kilometer on each side, exactly 1,000,000 square meters or 100 hectares. It is the usual metric unit for large areas.
City and district areas, national parks, reservoirs, islands and administrative regions are measured in square kilometers. Satellite imagery and land-cover studies report extents this way as well.
Acres to Hectares
One acres is 0.404686 hectares, and one hectares is 2.471054 acres.
A hectare is 10,000 square meters, or 0.01 square kilometers. It is the standard unit for farmland and land-title areas in Tanzania and most metric countries.
- 1 ac= 0.404686 ha
- 5 ac= 2.023428 ha
- 10 ac= 4.046856 ha
A hectare is exactly 10,000 square meters, the area of a square 100 meters on a side, and it equals 0.01 square kilometers. It is the metric unit of land area.
Farmland, forest, parks and large plots are measured in hectares across most of the world, and land registries in metric countries record titles in hectares. Sports fields and golf courses also appear in hectares.
Acres to Square feet
One acres is 43,560 square feet, and one square feet is 2.2957e-5 acres.
A square foot is 0.09290304 square meters. It is the standard unit for floor area and property listings in the United States and the UK.
- 1 ac= 43,560 ft²
- 5 ac= 217,800 ft²
- 10 ac= 435,600 ft²
A square foot is the area of a square with sides one foot long, exactly 0.09290304 square meters. It is a unit of area and not a unit of length.
Floor area in property listings, apartment sizes, tiles, paint coverage and roofing are quoted in square feet in the United States and several other markets. Carpets and timber are sold this way too.
Acres to Square inches
One acres is 6,272,640 square inches, and one square inches is 1.5942e-7 acres.
A square inch is 6.4516 square centimeters. It is used for small areas, and is the denominator in psi, the imperial pressure unit.
- 1 ac= 6,272,640 in²
- 5 ac= 31,363,200 in²
- 10 ac= 62,726,400 in²
Acres to Square yards
One acres is 4,840 square yards, and one square yards is 2.0661e-4 acres.
A square yard is 0.83612736 square meters, or 9 square feet. It is used for carpet, landscaping and fabric in imperial-measure countries.
- 1 ac= 4,840 yd²
- 5 ac= 24,200 yd²
- 10 ac= 48,400 yd²
Acres to Square miles
One acres is 0.001563 square miles, and one square miles is 640 acres.
A square mile is about 2.59 square kilometers, or exactly 640 acres. It is used for land and territory areas in the United States and the UK, and for large ranch or park sizes.
- 1 ac= 0.001563 mi²
- 5 ac= 0.007813 mi²
- 10 ac= 0.015625 mi²
A square mile is the area of a square one mile on each side, exactly 2.589988110336 square kilometers, or exactly 640 acres. It is built from the statute mile and never from the nautical mile.
Metropolitan areas, counties, states, large ranches and national parks are measured in square miles in those countries. Weather maps and watershed studies also report extents in square miles.
What acres are used for
An acre is 4,046.8564224 square meters, about 0.4047 hectares. It is the traditional land unit of the UK and US and is still used for land in parts of East Africa.
An acre is exactly 4,046.8564224 square meters, an area of 4,840 square yards, or one chain by one furlong. It is a unit of area, not of length.
Land titles, farm sizes, plots and ranches are described in acres in the United States, the United Kingdom and parts of the Commonwealth. Estate agents quote plot sizes in acres.
One acre equals 0.40468564224 hectares exactly, and a square mile holds exactly 640 acres. The site rounds displayed output, so a figure converted to hectares and back may return one digit away.
The classic mistake is treating an acre as a square of fixed side length; it is any shape with that area, and an acre is roughly 209 feet square only when square. Quoting acres from a deed written in hectares also invites error.
Acres and hectares both describe land, with one acre under half a hectare. A plot stated in hectares is about 2.47 times the same number of acres, so quoting the wrong unit makes land look far larger or smaller.
Every factor is an exact definition, so the only loss is display rounding. Land figures quoted in acres and hectares are usually rounded at the source.
Area factors are the square of the corresponding length factors, so the numbers move much faster than a reader expects. A square meter contains 10,000 square centimeters, and a square kilometer a million square meters, not a thousand.
The units that share a name across systems are still different sizes: a square mile and a square kilometer differ by a factor of about 2.59, and an acre is a fixed area rather than a square with equal sides, so it does not convert like the length units it is named after.
Land is where the reciprocal matters most, because acres and hectares are both in use for the same plots. When a figure moves between them, check it against a shape you can picture — a hectare is a square 100 meters on each side — rather than against the number alone.
Tanzania reference points
Real quantities, converted into acres.
The total surface area of Tanzania, including Zanzibar
947,303 km² = 234,083,669.17999 ac
Source: UN Statistics Division — World Statistics Pocketbook, country profile: Tanzania · verified 2026-09-14
Acres conversion tables
Acres to Square millimeters
| Acres (ac) | Square millimeters (mm²) |
|---|---|
| 1 | 4,046,856,422.400001 |
| 2 | 8,093,712,844.800001 |
| 3 | 12,140,569,267.2 |
| 4 | 16,187,425,689.600002 |
| 5 | 20,234,282,112 |
| 10 | 40,468,564,224 |
| 25 | 101,171,410,560.00002 |
| 50 | 202,342,821,120.00003 |
| 100 | 404,685,642,240.00006 |
Acres to Square centimeters
| Acres (ac) | Square centimeters (cm²) |
|---|---|
| 1 | 40,468,564.224 |
| 2 | 80,937,128.448 |
| 3 | 121,405,692.672 |
| 4 | 161,874,256.896 |
| 5 | 202,342,821.12 |
| 10 | 404,685,642.24 |
| 25 | 1,011,714,105.6 |
| 50 | 2,023,428,211.2 |
| 100 | 4,046,856,422.4 |
Acres to Square meters
| Acres (ac) | Square meters (m²) |
|---|---|
| 1 | 4,046.856422 |
| 2 | 8,093.712845 |
| 3 | 12,140.569267 |
| 4 | 16,187.42569 |
| 5 | 20,234.282112 |
| 10 | 40,468.564224 |
| 25 | 101,171.41056 |
| 50 | 202,342.82112 |
| 100 | 404,685.64224 |