The Surface Area Unit Converter converts an area from one unit to every other common unit at once — square millimeters, centimeters, meters and kilometers, square inches, feet and yards, acres and hectares.
Surface Area Unit Converter
Convert a surface area between square millimetres, centimetres, metres, kilometres, inches, feet, yards, acres and hectares.
It converts through square meters using exact factors (1 ft = 0.3048 m, so 1 ft² = 0.09290304 m²). Enter a value and choose its unit below.
Formula
Area in new unit = Area × (factor of old unit ÷ factor of new unit)
Where each factor is the unit’s size in square meters:
- 1 mm² = 0.000001 m²; 1 cm² = 0.0001 m²; 1 km² = 1,000,000 m²
- 1 in² = 0.00064516 m²; 1 ft² = 0.09290304 m²; 1 yd² = 0.83612736 m²
- 1 acre = 4,046.8564224 m²; 1 hectare = 10,000 m²
How the Calculation Works
Step 1: Convert your value to square meters by multiplying by its factor.
Step 2: Divide by the factor of each target unit.
Step 3: Show every result together, so you can read off whichever unit you need.
Area factors are the square of length factors. Because 1 m = 100 cm, 1 m² = 100 × 100 = 10,000 cm² — not 100 cm².
Variables Explained
| Unit | Symbol | Typical use |
|---|---|---|
| Square millimeter / centimeter | mm², cm² | Small parts, cross-sections |
| Square meter | m² | Rooms, walls, metric projects |
| Square inch / foot / yard | in², ft², yd² | US construction, flooring, carpet |
| Acre, hectare | ac, ha | Land |
| Square kilometer | km² | Large land areas |
Example Calculation
Square meters to square feet
Given: 100 m²
Calculation: 100 ÷ 0.09290304
Result: ≈ 1,076.39 ft²
Square feet to square meters
Given: 250 ft²
Calculation: 250 × 0.09290304
Result: ≈ 23.23 m²
Area Conversion Table
| From | To | Multiply by |
|---|---|---|
| ft² | m² | 0.09290304 |
| m² | ft² | 10.7639 |
| in² | cm² | 6.4516 |
| m² | in² | 1,550.003 |
| yd² | m² | 0.83613 |
| ft² | in² | 144 |
| yd² | ft² | 9 |
| acre | ft² | 43,560 |
| acre | m² | 4,046.856 |
| hectare | acre | 2.47105 |
| km² | acre | 247.105 |
Dimensions Explained
Why not just multiply by the length factor?
Area has two dimensions, so the length factor is applied twice. 1 yd = 3 ft, but 1 yd² = 3 × 3 = 9 ft².
Surface area vs area
The units are the same. Whether the number is the area of a floor or the surface area of a sphere, it converts in exactly the same way.
Frequently Asked Questions
How do you convert square feet to square meters?
Multiply by 0.09290304 (or divide by 10.7639).
How many square feet are in a square meter?
About 10.7639 ft².
How many square centimeters are in a square meter?
10,000 cm², because 100 × 100 = 10,000.
How many square feet are in an acre?
Exactly 43,560 ft².
How do you convert square inches to square feet?
Divide by 144.
What is the difference between an acre and a hectare?
A hectare is 10,000 m², about 2.471 acres. An acre is about 4,047 m².