Residential lot sizes
US zoning frequently specifies minimum lot sizes in fractions of an acre. A quarter acre is 10,890 sq ft and a fifth of an acre is 8,712 sq ft — the difference decides whether a subdivision plan is compliant.
Area
Convert acres to square feet
1 acre equals 43,560 square feet. Enter a value below to convert instantly.
Acres to square feet is a land conversion with a fixed, memorable value: one acre is exactly 43,560 square feet. The number looks arbitrary but is not — it comes from an acre being one chain wide by one furlong long, or 66 ft by 660 ft.
Need the other direction? Convert square foot to acre →
Formula
Multiply the number of acres by 43560 to get square feet.
Step by step
- Start with 1 ac.
- Multiply by the conversion factor 43560.
- 1 × 43560 = 43,560 ft².
Acres to Square Feet conversion table
| Acres (ac) | Square Feet (ft²) |
|---|---|
| 1 | 43,560 |
| 2 | 87,120 |
| 3 | 130,680 |
| 5 | 217,800 |
| 10 | 435,600 |
| 20 | 871,200 |
| 50 | 2,178,000 |
| 100 | 4,356,000 |
| 500 | 21,780,000 |
| 1,000 | 43,560,000 |
Where acres and square feet are used together
Agricultural yields and inputs
Seed, fertiliser and yield are quoted per acre in the US and per hectare elsewhere. Converting the area is the first step; converting the rate is a second, separate one.
Sports fields as a mental reference
An American football field including end zones is about 57,600 sq ft, or roughly 1.32 acres. The playing area alone is closer to 1.1 acres — a useful sanity check when a listed acreage feels wrong.
Land purchase and property tax
Assessments and price-per-acre comparisons need consistent units. A parcel listed at 87,120 sq ft is exactly two acres; listings sometimes state one figure and not the other.
Everyday acres worth knowing
Values people actually look up, with the reason each one comes up. Every figure is calculated with the same engine as the converter above.
| Acre (ac) | Square Foot (ft²) | What it is |
|---|---|---|
| 0.1 | 4,356 | A small urban lot |
| 0.25 | 10,890 | A quarter-acre lot |
| 0.5 | 21,780 | A half-acre lot |
| 1 | 43,560 | The base conversion |
| 2 | 87,120 | A large residential parcel |
| 5 | 217,800 | A smallholding |
| 10 | 435,600 | A small farm parcel |
| 640 | 27,878,400 | One square mile — a section |
How these two units are defined
The acre has no metric definition of its own — it is defined through the square yard, giving exactly 4,046.8564224 m² or exactly 43,560 square feet. Historically it was the area a yoke of oxen could plough in a day, which is why its shape (long and narrow, one furlong by one chain) is baked into the number. The hectare, at 10,000 m², is the metric land unit and is about 2.47 acres.
Rounding and precision
43,560 is exact, so the conversion adds nothing. Surveyed parcel areas are typically stated to the nearest hundredth of an acre, which is about 436 sq ft — so quoting a lot as 0.2503 acres is finer than the survey supports. Where an area decides compliance with a zoning minimum, use the figure on the recorded survey rather than a converted one, and check whether the rule counts gross or net area.
Mistakes people make with this conversion
-
Assuming an acre is square
An acre is an area, not a shape. The traditional acre is 66 ft by 660 ft; a square acre is about 208.7 ft on a side. Frontage requirements are a separate constraint from area.
-
Mixing acres and hectares
A hectare is 2.471 acres. Agricultural figures quoted per hectare are roughly 2.5 times the per-acre equivalent, which is easy to misread as a different crop performance.
-
Confusing an acre with an acre-foot
An acre-foot is a volume — one acre covered to a depth of one foot, about 1,233 m³. It appears constantly in water rights and irrigation, and it is not an area at all.
Read more about these units
Sources for this page
- Special Publication 811 — Guide for the Use of the International System of Units (SI)
- Publications and Documentary Standards (NIST Handbook 44, Handbook 133)
Content on this page last reviewed 12 August 2026. Spotted an error? Report it — see also how these values are calculated.
Convert Acre to other area units
1 ac expressed in every other area unit on this site.
- Square Meter m² 4,046.8564
- Square Kilometer km² 0.0040468564
- Square Hectometer hm² 0.40468564
- Square Dekameter dam² 40.468564
- Square Decimeter dm² 404,685.64
- Square Centimeter cm² 40,468,564
- Square Millimeter mm² 4,046,856,400
- Square Micrometer µm² 4.0468564e+15
- Square Nanometer nm² 4.0468564e+21
- Hectare ha 0.40468564
- Are a 40.468564
- Square Mile mi² 0.0015625
- Acre ac 1
- Square Yard yd² 4,840
- Square Foot ft² 43,560
- Square Inch in² 6,272,640
- Square Mil mil² 6,272,640,000,000
- Circular Inch circ in 7,986,573.3
- Circular Mil cmil 7,986,573,300,000
- Square Rod rd² 160
- Square Perch perch² 160
- Square Pole pole² 160
- Square Chain ch² 10
- Rood rood 4
- Section section 0.0015625
- Township township 0.000043402778
- Homestead homestead 0.00625
- Sabin sabin 43,560
- Square Mile (US survey) mi² (US) 0.0015624938
- Acre (US survey) ac (US) 0.999996
- Square Foot (US survey) ft² (US) 43,559.826
- Square Rod (US survey) rd² (US) 159.99936
- Barn b 4.0468564e+31
- Electron Cross Section σₑ 6.0832492e+31
- Arpent (area) arpent 1.1836745
- Cuerda cuerda 1.0296308
- Plaza plaza 0.63232132
- Varas Castellanas Cuad vara² (cast) 5,791.6733
- Varas Conuqueras Cuad vara² (con) 643.51925
- Pyeong 평 1,224.1741
- Hop (area) 홉 12,241.741
- Jak (area) 작 122,417.41
- Myo 무 40.805802
- Danbo 단보 4.0805802
- Jeongbo 정보 0.40805802
About the acre
The acre (ac) is a Imperial unit of area. 43,560 square feet — the traditional unit for farmland and property lots.
About the square foot
The square foot (ft²) is a Imperial unit of area.
Related conversions
Frequently asked questions
How many square feet are in an acre?
Exactly 43,560. The figure comes from the acre's definition as one chain (66 ft) by one furlong (660 ft).
How big is a quarter-acre lot?
10,890 sq ft, or 1,011.7 m². If it were square it would be about 104 ft on a side, though most quarter-acre lots are longer than they are wide.
How many acres are in a square mile?
Exactly 640 acres. This is why US land is subdivided into square-mile 'sections' of 640 acres, quarter sections of 160, and so on.
How many square feet are in a acre?
One acre equals 43,560 square feet.
How do you convert acres to square feet?
Multiply the number of acres by 43560 to get square feet.
What is 1 square foot in acres?
One square foot equals 0.000022956841 acres.
When would I convert acres to square feet?
This conversion is common when real estate, flooring, land plots, gardens, and paint coverage.