How many square feet are in an acre?
One international acre equals exactly 43,560 square feet. To convert square feet to acres, divide the area by 43,560.
To convert acres back to square feet, multiply by 43,560. This relationship applies to area, not boundary length.
Common lot-size examples
A 10,890-square-foot lot is 0.25 acre. A half-acre lot contains 21,780 square feet.
A 100,000-square-foot parcel is approximately 2.2957 acres. For property descriptions, retain enough decimal places to match the source record.
Calculate area before converting
For a rectangular lot, multiply length by width to get square feet, then divide by 43,560. A 200 ft by 100 ft parcel is about 0.4591 acre.
Irregular parcels require a survey, mapped coordinates, or decomposition into smaller shapes. A rectangle estimate may not match the legal area.
Avoid linear-foot confusion
Square feet measure surface area, while linear feet measure distance. A fence estimate uses boundary length; a lawn or parcel estimate uses area.
Local records may use hectares or regional units. Confirm the jurisdiction and definition before comparing listings or calculating materials.