How to use
- Type the area exactly as the document states it. Do not convert in your head first.
- Pick the unit that matches the document: acres, square feet, square yards, square meters, hectares, or square miles.
- Press Calculate. Every other unit updates from that single input.
- Press Reset to clear the value. The unit menu stays on your last choice until you change it.
How it's calculated
1 square yard = 9 square feet
1 hectare = 10,000 square meters
1 square mile = 640 acres
1 square foot = 0.3048 × 0.3048 square meters
An acre is defined as 43,560 square feet. Using the international foot of exactly 0.3048 meters, an acre is 43,560 × 0.3048² square meters, about 4,046.86 square meters. A hectare is 10,000 square meters by definition, and a square mile is 640 acres.
Room-sized jobs should stay in feet. The area calculator handles circles and triangles. The square footage calculator adds rooms. This page is for lots, fields, and anything large enough that acres are the natural unit.
Worked example
One acre is 43,560 square feet and 4,840 square yards, because 43,560 ÷ 9 = 4,840. The same acre is about 0.4047 hectares. A half-acre lot is 21,780 square feet. A quarter-acre lot is 10,890 square feet.
Assumptions and sources
The international foot (0.3048 m exactly) is the foot used here. NIST retired the US survey foot for most work after 2022; older plats that say “US survey foot” can differ by a very small amount. This tool does not read a deed and does not know easements, so the number is the geometric area you typed, not a legal lot size.
FAQ
How many square feet are in an acre?
43,560 square feet.
How many acres are in a square mile?
640 acres.
How do I turn square meters into acres?
Divide square meters by 4,046.8564224, which is 43,560 times 0.3048 squared. The converter does that when you pick square meters.
Is a hectare the same as an acre?
No. A hectare is 10,000 square meters, about 2.471 acres. An acre is smaller.