An acre is defined as exactly 43,560 square feet — the standard US land-measurement unit.
How it works
Multiplying acres by 43,560 gives square feet; dividing square feet by that same constant gives acres back. Type into either field and the other updates instantly.
What this does not include
This does not include square meters or hectares — this calculator stays within the US customary land-measurement system.
How to use this calculator
- Enter a value in either acres or square feet — the other field fills in automatically.
Frequently asked questions
Where does the 43,560 figure come from?
It’s the standard definition of an acre in the US customary system, historically derived from a furlong by a chain (660 ft × 66 ft).
Where is this conversion most commonly needed?
Comparing a property listing’s lot size in acres against a building’s square footage, or real estate and agricultural land measurements.
Is an acre a fixed shape?
No — an acre measures area only, not a specific shape; a square acre and a long, narrow acre-sized strip both cover the same 43,560 square feet.
