How this calculator works
Pick a from-unit and a to-unit and type a value; the conversion and the exact factor for that pair appear instantly. Land is usually measured in acres or hectares, floor space in square feet or square meters, and large territories in square kilometers or square miles, so this converter covers the units that come up in real estate, farming and geography.
Every unit is defined in square meters, so any pair converts through a single exact ratio. Imperial area units all derive from the exact 1959 international yard (0.9144 m); an acre is, by definition, 4,840 square yards, and a hectare is, by definition, exactly 10,000 square meters.
How it converts
result = value × (square meters per from-unit) ÷ (square meters per to-unit)Exact anchors: 1 ha = 10,000 m² · 1 acre = 4,840 yd² = 4,046.8564224 m² · 1 mi² = 640 acres = 2,589,988.110336 m²Worked example: 640 acres to square miles
- 640 acres × 4,046.8564224 m²/acre = 2,589,988.110336 m².
- 1 mi² = 1,609.344 m long × 1,609.344 m wide = 2,589,988.110336 m².
- The two match exactly, confirming 640 acres = 1 square mile — the standard survey relationship.
Frequently asked questions
How many acres are in a square mile?
Exactly 640 acres, since a square mile is 1,609.344 m on a side and an acre is 4,840 square yards; this exact 640:1 ratio dates from historical English land surveying.
Is a hectare bigger than an acre?
Yes. One hectare (10,000 m²) is about 2.47 acres, so an acre is roughly 40% of a hectare.
What is the difference between acres and acre-feet?
An acre measures area only. An acre-foot is a volume, one acre in area covered to a depth of one foot, commonly used for reservoir and irrigation water volumes — use the volume converter for that.
Why does my property deed list both acres and square feet?
Small residential lots are often easier to picture in square feet (1 acre = 43,560 ft²), while zoning and tax records typically use acres for consistency across larger and smaller parcels.
How many square feet are in an acre?
Exactly 43,560 square feet. This follows from two relationships already used on this page: an acre is 4,840 square yards, and each square yard is 9 square feet (3 feet × 3 feet), so 4,840 × 9 = 43,560.