One acre is exactly 43,560 square feet. That number is part of the acre's definition, so there is no rounding in this direction: multiply the acres by 43,560 and the answer is exact. Homeowners, builders and buyers in the United States use this conversion constantly, because lot sizes are listed in acres while setbacks, building footprints, driveways and lawns are planned in square feet.
Formula
Acres to Square Feet conversion table
| Acres | Square Feet |
|---|---|
| 1 ac | 43,560 ft² |
| 2 ac | 87,120 ft² |
| 3 ac | 130,680 ft² |
| 4 ac | 174,240 ft² |
| 5 ac | 217,800 ft² |
| 6 ac | 261,360 ft² |
| 7 ac | 304,920 ft² |
| 8 ac | 348,480 ft² |
| 9 ac | 392,040 ft² |
| 10 ac | 435,600 ft² |
| 12 ac | 522,720 ft² |
| 15 ac | 653,400 ft² |
| 20 ac | 871,200 ft² |
| 25 ac | 1,089,000 ft² |
| 30 ac | 1,306,800 ft² |
| 40 ac | 1,742,400 ft² |
| 50 ac | 2,178,000 ft² |
| 60 ac | 2,613,600 ft² |
| 70 ac | 3,049,200 ft² |
| 75 ac | 3,267,000 ft² |
| 80 ac | 3,484,800 ft² |
| 90 ac | 3,920,400 ft² |
| 100 ac | 4,356,000 ft² |
Where you’ll use it
A half-acre lot is 21,780 square feet and a quarter acre is 10,890. A listing that says 0.17 acres means about 7,405 square feet of land. Zoning codes often state minimum lot sizes either way, so you will see both on the same page of a planning document. Landscapers and turf suppliers also start from acreage and work down to square feet when estimating seed, sod or fertilizer for large lawns and paddocks.
Tip: An acre has no fixed shape. If it were a perfect square, each side would be about 208.71 feet. A common mistake is to picture an acre as 200 by 200 feet, which is only 40,000 square feet and about 8% short.