Acreage calculator
Enter your lot's sides and see how many acres it is, even for a lot that isn't square, with the shape drawn to scale.
Your lot is
1.000 acres
Those sides can't meet: one side (or the diagonal) is as long as the others put together. Check the measurements.
- Square feet
- 43,560 sq ft
- Square yards
- 4,840 sq yd
- Hectares
- 0.405 ha
- Square meters
- 4,047 m²
- Square miles
- 0.0016 sq mi
- Perimeter
- 835 ft
- Same area as a square
- 208.7 ft on a side
- Land price
- Per square foot
Your deed, plat or survey gives the legal acreage. Measurements taken along a slope read a little more than the level (map) area.
How to calculate acreage
Find the area in square feet, then divide by 43,560, the number of square feet in an acre. Measure in feet, or convert first: a yard is 3 feet, a chain is 66 feet and a mile is 5,280 feet.
- Rectangle: length × width
- Triangle from its three sides (Heron's formula): with s = half the perimeter, area = √(s × (s − A) × (s − B) × (s − C))
- Four-sided lot: a diagonal splits it into two triangles; work out each and add them. Four sides alone aren't enough, because the same sides can lean into different shapes.
- Circle: 3.1416 × radius²
- Acres = square feet ÷ 43,560
Worked example
A lot with sides of 210, 180, 230 and 190 feet, and 290 feet corner to corner. The diagonal makes two triangles: 210, 180 and 290 ft is 18,804 sq ft, and 230, 190 and 290 ft is 21,816 sq ft. Together that's 40,620 sq ft, and 40,620 ÷ 43,560 = 0.933 acres. Press "Irregular lot" above to see it drawn.
Acre size chart
Square feet in common lot and field sizes, and how long each side would be if the land were a square.
| Acres | Square feet | Hectares | Square, each side |
|---|---|---|---|
| 0.1 | 4,356 | 0.040 | 66.0 ft |
| 0.25 | 10,890 | 0.101 | 104.4 ft |
| 0.5 | 21,780 | 0.202 | 147.6 ft |
| 1 | 43,560 | 0.405 | 208.7 ft |
| 2 | 87,120 | 0.809 | 295.2 ft |
| 5 | 217,800 | 2.023 | 466.7 ft |
| 10 | 435,600 | 4.047 | 660.0 ft |
| 20 | 871,200 | 8.094 | 933.4 ft |
| 40 | 1,742,400 | 16.187 | 1,320.0 ft |
| 80 | 3,484,800 | 32.375 | 1,866.8 ft |
| 160 | 6,969,600 | 64.750 | 2,640.0 ft |
| 640 | 27,878,400 | 258.999 | 5,280.0 ft |
Land measurement units
| Unit | Equals |
|---|---|
| 1 acre | 43,560 sq ft = 4,840 sq yd = 10 square chains = 0.4047 ha |
| 1 square mile | 640 acres = 259.0 ha |
| 1 hectare | 2.471 acres = 10,000 m² (100 m × 100 m) |
| 1 chain | 66 ft (Gunter's chain, used in older deeds) |
| 1 mile | 5,280 ft = 80 chains |
Acreage questions
How many acres is a football field?
1.32 acres, counting the end zones. An NFL field is 360 feet long and 160 feet wide (NFL 2026 Official Playing Rules, Rule 1, Section 1), so it covers 57,600 sq ft. Between the goal lines alone it's 1.10 acres. An acre is about 76% of a whole field.
How many acres are in a square mile?
640. A mile is 5,280 feet, so a square mile is 27,878,400 sq ft, and that ÷ 43,560 = 640 acres. In the US public land survey a square-mile section is 640 acres, a quarter section 160 and a quarter-quarter 40.
How big is an acre?
43,560 square feet: about 208.7 feet on each side if it's square, though an acre can be any shape. Ten acres is 660 feet (0.125 mile) on a side. The chart above has other sizes.
How many acres are in a hectare?
2.471 acres. A hectare is a 100 by 100 meter square, 10,000 square meters. To go the other way, an acre is 0.4047 hectare.
How many acres is a soccer field?
Between 1.58 and 2.04 acres for an international match field, which must be 100–110 m long and 64–75 m wide (IFAB Laws of the Game, Law 1.4, international matches). Youth and park fields are often smaller; measure yours and enter it above.
How do I find the acreage of an irregular lot?
Choose "Four sides (irregular lot)", enter the four sides in order around the lot, and measure one diagonal from corner to corner. The calculator splits the lot into two triangles and draws it so you can check it looks right. For more corners, split the lot into triangles and rectangles, work out each, and add the acres. Your deed, plat or county GIS map gives the surveyed figure. For a small yard or a room, the square footage calculator works in square feet; to fence the lot, use the perimeter with the fence calculator.