Convert square feet to acres, reverse acres to square feet, or estimate rectangular lot acreage from length and width.
Calculator
1 acre = exactly 43,560 square feet. Length x width applies to rectangular lots.
Area Conversion Results
Compare acres and square feet with other common land-area units and review the exact calculation.
Area Compared with One Acre
Equivalent Areas
| Measurement | Value | Calculation note |
|---|
Convert square feet and acres in either direction
Use Square feet to acres when a deed, listing, floor plan, or site plan gives total area in square feet. Use Acres to square feet when you need the equivalent land area for a project estimate. The lot-dimensions mode first multiplies an entered rectangular length and width, then converts that square-foot total to acres.
Square feet to acres formula
One acre contains exactly 43,560 square feet. Divide square feet by 43,560 to convert an area to acres.
acres = square feet / 43,560
For example, 20,000 square feet divided by 43,560 is approximately 0.459137 acres. The calculator keeps the full result internally and rounds only the displayed value.
Acres to square feet formula
Multiply acres by 43,560 to reverse the conversion.
square feet = acres x 43,560
For example, 2.5 acres is 2.5 x 43,560 = 108,900 square feet. A quarter acre is 10,890 square feet, and a half acre is 21,780 square feet.
Calculate acreage from lot dimensions
For a rectangular parcel measured in feet, multiply length by width to find square feet, then divide by 43,560. A 200-foot by 100-foot lot contains 20,000 square feet, or about 0.459 acre. Real parcels may be irregular, curved, sloped, or described by bearings and distances; a simple rectangle is only appropriate when those entered dimensions represent the actual boundaries.
rectangular acres = length in feet x width in feet / 43,560
Common acres to square feet chart
| Acres | Square feet | Square miles |
|---|---|---|
| 0.1 acres | 4,356 sq ft | 0.00015625 sq mi |
| 0.25 acres | 10,890 sq ft | 0.000390625 sq mi |
| 0.5 acres | 21,780 sq ft | 0.00078125 sq mi |
| 1 acre | 43,560 sq ft | 0.0015625 sq mi |
| 2 acres | 87,120 sq ft | 0.003125 sq mi |
| 5 acres | 217,800 sq ft | 0.0078125 sq mi |
| 10 acres | 435,600 sq ft | 0.015625 sq mi |
| 11 acres | 479,160 sq ft | 0.0171875 sq mi |
| 20 acres | 871,200 sq ft | 0.03125 sq mi |
| 40 acres | 1,742,400 sq ft | 0.0625 sq mi |
Common square feet to acres chart
| Square feet | Acres | Square meters |
|---|---|---|
| 1,000 sq ft | 0.0229568 acres | 92.90 sq m |
| 2,500 sq ft | 0.0573921 acres | 232.26 sq m |
| 5,000 sq ft | 0.114784 acres | 464.52 sq m |
| 10,000 sq ft | 0.229568 acres | 929.03 sq m |
| 20,000 sq ft | 0.459137 acres | 1,858.06 sq m |
| 43,560 sq ft | 1 acres | 4,046.86 sq m |
| 50,000 sq ft | 1.14784 acres | 4,645.15 sq m |
| 100,000 sq ft | 2.29568 acres | 9,290.30 sq m |
| 435,600 sq ft | 10 acres | 40,468.56 sq m |
| 1,000,000 sq ft | 22.9568 acres | 92,903.04 sq m |
Equivalent land-area units
The result panel also reports square yards, square meters, hectares, and square miles. One square yard contains 9 square feet. One square foot equals exactly 0.09290304 square meter under the international foot definition. A hectare contains 10,000 square meters, while one square mile contains 640 acres or 27,878,400 square feet.
Why an acre is not a fixed shape
An acre measures area, not length. It can be a square, rectangle, triangle, or irregular parcel as long as the enclosed area is 43,560 square feet. If one acre were a perfect square, each side would be about 208.71 feet, but that side length is not part of the definition. The current NIST Handbook 133 area tables state the exact 43,560-square-foot relationship and explain that an acre need not be square or rectangular.
Square miles versus miles
Area must remain in squared units. Asking how many miles are in 11 acres mixes an area with a linear distance. The comparable area unit is square miles: 11 acres divided by 640 equals 0.0171875 square mile. A boundary length in miles cannot be determined from acreage alone because parcels with the same area can have very different shapes and perimeters.
Property records and survey accuracy
Calculated acreage is only as reliable as the entered area or dimensions. Tax records, listing descriptions, recorded plats, geographic information systems, and physical surveys can differ because of rounding, easements, road rights-of-way, water boundaries, mapping methods, or whether gross and usable area are reported. For a purchase, boundary dispute, subdivision, permitting decision, or legal description, use the recorded documents and a licensed land surveyor rather than an online estimate.
Related area calculations
Use the square footage calculator when the area must first be found from room, wall, circle, or triangle dimensions. Use the acres to square feet calculator for the reverse conversion. To estimate a rectangular parcel, select lot-dimensions mode in this calculator. For material projects, do not treat acreage as usable coverage until setbacks, openings, slopes, waste, and site-specific exclusions have been considered.
Frequently asked questions
How many square feet are in an acre?
There are exactly 43,560 square feet in one acre.
How many acres are in 10,000 square feet?
10,000 divided by 43,560 is approximately 0.229568 acres.
Is 200 feet by 200 feet one acre?
No. That rectangle contains 40,000 square feet, which is about 0.918274 acre.
How many acres are in a square mile?
There are 640 acres in one square mile.
Can I calculate an irregular lot with one length and width?
Not accurately unless those dimensions truly describe an equivalent rectangle. Divide an irregular plan into measurable shapes or use survey/GIS area data.