# What is the acreage of my land?

Computes the acreage of a rectangular, triangular, trapezoid or circular plot from its measurements, or of an area typed in any unit, in acres, square feet, square yards, square metres and hectares.

- Page: https://www.acalculator.org/construction/acreage-calculator
- JSON spec: https://www.acalculator.org/construction/acreage-calculator.json
- Version: db0f939563d4

## Default answer

Example with the default inputs (Shape of the land Rectangle or square, Length 400 ft, Width 250 ft): In acres, the land measures 2.2957; in square feet, 100,000.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| shape | Shape of the land | The shape of the plot, or "I know the area" to convert an area to acres. |
| l | Length | The length of the rectangle. |
| w | Width | The width of the rectangle, at right angles to the length. |
| b | Base | The base of the triangle. |
| a | Top side | The first of the two parallel sides of the trapezoid. |
| c | Bottom side | The second of the two parallel sides of the trapezoid. |
| h | Height | The height of the triangle or trapezoid, at right angles to the base or the parallel sides. |
| d | Diameter | The diameter of the circle. |
| area | Area | An area in any unit, to convert to acres. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| acres | Acres | The area in acres (1 acre = 43,560 square feet). |
| squareFeet | Square feet | The area in square feet. |
| squareYards | Square yards | The area in square yards (9 square feet each). |
| squareMeters | Square metres | The area in square metres. |
| hectares | Hectares | The area in hectares (10,000 square metres each). |

## Method

Area = length × width (rectangle), ½ × base × height (triangle), ½ × (a + b) × height (trapezoid), or π × d² ÷ 4 (circle); acres = square feet ÷ 43,560.

## Assumptions

- The land is flat: the area is measured on a level plane, as a survey does, not along slopes.
- An acre is 43,560 square feet of the international foot, 4,046.8564224 m² exactly.
- A plot with an irregular shape can be split into rectangles, triangles and trapezoids, with the acreages added.

## Worked examples

1. shape = rect, l = 121.92, w = 76.2 gives acres = 2.295684, squareFeet = 100,000, squareYards = 11,111.111111, squareMeters = 9,290.304, hectares = 0.92903. Source: NIST Handbook 44, Appendix C (1 acre = 43,560 ft², 1 ft = 0.3048 m).
2. shape = rect, l = 201.168, w = 20.1168 gives acres = 1, squareFeet = 43,560, squareMeters = 4,046.856422. Source: NIST Handbook 44, Appendix C: 1 furlong = 660 ft, 1 chain = 66 ft, 1 acre = 43,560 ft² = 4,046.8564224 m² (international foot).
3. shape = area, area = 10,000 gives acres = 2.471054, hectares = 1, squareFeet = 107,639.104167. Source: NIST Handbook 44, Appendix C (1 hectare = 10,000 m²; 1 acre = 4,046.8564224 m²).
4. shape = tri, b = 91.44, h = 60.96 gives acres = 0.688705, squareFeet = 30,000.
5. shape = trap, a = 60.96, c = 91.44, h = 45.72 gives acres = 0.860882, squareFeet = 37,500.
6. shape = circle, d = 100 gives squareMeters = 7,853.981634, acres = 1.940761.
7. shape = rect, l = 132.777519, w = 30.48 gives acres = 1.00005, squareFeet = 43,562.178. Source: NIST Handbook 44, Appendix C (1 acre = 43,560 ft²).

## FAQ

### How many square feet are in an acre?

An acre is exactly 43,560 square feet. That is 4,840 square yards, or 4,046.8564224 square metres. Historically it was a strip one furlong (660 ft) long and one chain (66 ft) wide: 660 × 66 = 43,560.

### How do I calculate the acreage of a lot?

Find the area in square feet and divide by 43,560. A rectangular lot 400 ft by 250 ft is 400 × 250 = 100,000 ft², and 100,000 ÷ 43,560 = 2.2957 acres. For a lot measured in metres, divide the square metres by 4,046.8564224.

### How long is each side of a square acre?

The square root of 43,560 ft², which is about 208.71 ft (63.61 m). A square one acre in size is about 208.7 ft on each side.

### How many acres is a hectare?

One hectare is 10,000 m², which is 2.4711 acres. One acre is 0.4047 hectare.

### How do I find the acreage of an irregular plot?

Split it into shapes this calculator knows: rectangles, triangles and trapezoids. Find the acreage of each and add them. A plot with four straight sides that are not parallel can be split into two triangles along a diagonal.

### Does a sloping plot have more acres?

No. Acreage is measured on a level plane, as a survey measures it, so a hillside counts by its footprint, not by the length of the slope. Measure the distances level, or use the lengths from a survey or a plat.

## Sources

- NIST Handbook 44 (2024), Appendix C, General Tables of Units of Measurement: 1 acre = 43,560 ft² = 4,840 yd²; 1 furlong = 660 ft; 1 chain = 66 ft; 1 hectare = 10,000 m². https://www.nist.gov/pml/owm/nist-handbook-44-current-edition
- National Institute of Standards and Technology and NOAA, Deprecation of the United States Survey Foot, Federal Register 85 FR 62698 (2020): from 2023, US lengths and areas use the international foot, 1 ft = 0.3048 m exactly. https://www.federalregister.gov/d/2020-21902
- OpenStax, Prealgebra 2e, §9.4 Use Properties of Rectangles, Triangles, and Trapezoids, and §9.5 Solve Geometry Applications: Circles and Irregular Figures. https://openstax.org/books/prealgebra-2e/pages/9-4-use-properties-of-rectangles-triangles-and-trapezoids