Square Meter Calculator
This square meter calculator multiplies a length by a width, each in meters, centimeters, millimeters, feet or inches. It totals as many areas as you add, in square meters (m², often typed m2), square feet, square centimeters and hectares. To see how big a room is in square meters, the room size table below turns 16 to 48 m² into square feet and example dimensions.
How to calculate square meters
Multiply the length in meters by the width in meters. The square meter, the SI unit of area, is a square 1 m on each side, per NIST.
Square meters = length in m × width in m
- Measure wall to wall at floor level; in feet, the rectangle area calculator gives square feet.
- Convert both sides to meters, or set each side's unit in the calculator.
- Multiply, then round.
The steps are the same in feet; see how to calculate square feet for L-shapes and odd rooms.
From centimeters, millimeters, feet or inches
Divide centimeters by 100 before you multiply, or divide the finished square centimeters by 10,000, because 1 m² is 100 × 100 cm.
| You measured in | Convert each side to meters | Or convert the finished area |
|---|---|---|
| Centimeters | Divide by 100 | cm² ÷ 10,000 |
| Millimeters | Divide by 1,000 | mm² ÷ 1,000,000 |
| Feet | Multiply by 0.3048 | sq ft × 0.09290304 |
| Inches | Multiply by 0.0254 | sq in × 0.00064516 |
All four factors are exact, from NIST's foot of 0.3048 m and inch of 0.0254 m.
Mixed units work: enter 4.2 m by 360 cm and the calculator returns 15.12 m².
Already have square feet? Use the square feet to square meters converter.
Common room sizes in square meters and square feet
A 4 by 3 m room is 12 m², about 129 square feet; multiply any m² figure by 10.7639 for square feet.
The room sizes people look up most, each as length × width in meters and square meters × 10.7639 in square feet:
| Room size | Square feet | Example dimensions (m) |
|---|---|---|
| 16 m² | 172.2 | 4 x 4, 3.2 x 5, 2.5 x 6.4 |
| 20 m² | 215.3 | 4 x 5, 3.2 x 6.25, 2.5 x 8 |
| 23 m² | 247.6 | 4 x 5.75, 4.6 x 5 |
| 24 m² | 258.3 | 4 x 6, 4.8 x 5, 3 x 8 |
| 30 m² | 322.9 | 5 x 6, 4 x 7.5, 3 x 10 |
| 32 m² | 344.4 | 4 x 8, 5 x 6.4 |
| 48 m² | 516.7 | 6 x 8, 4 x 12 |
Typical sizes are in standard room sizes, average bedroom size and average apartment size; other figures go through the square meters to square feet converter.
L-shaped and other shapes
Split the room into rectangles and add them. A 3.2 by 2.8 m area (8.96 m²) plus a 2.1 by 1.5 m alcove (3.15 m²) is 12.11 m²; enter each as its own area. The square footage calculator also takes meters and gives the total square footage of mixed rectangles, circles and triangles.
Base × height ÷ 2. A corner with a 4 m base and 3 m height is 6 m². The triangle calculator also takes three sides, in feet.
π × radius². A round patio 3 m across is 3.1416 × 1.5 × 1.5 = 7.07 m². See the circle calculator (feet).
Use pieces or offsets in the irregular shape calculator.
Flooring, paint and tile
Add waste for flooring and tile; subtract openings for paint.
A 4.2 by 3.6 m bedroom plus 10 percent for cuts, or 179 sq ft. The flooring calculator sets waste by material, in feet.
A 5.5 by 2.6 m wall (14.3 m²) minus a 2.0 by 0.9 m door (1.8 m²). The wall calculator repeats it for every wall, and the paint calculator turns it into gallons (both in feet).
Common mistakes
Most wrong m² answers come from mixing units or rounding too soon.
It's 10,000. Dividing by 100 makes it 100 times too big.
4.2 × 360 is meaningless. Convert first.
That's cubic meters, for concrete, not flooring.
3.64 × 4.18 is 15.22 m², but rounded to 3.6 × 4.2 it's 15.12.
Frequently asked questions
How do I calculate square meters?
Length in meters times width in meters: 4 m by 5 m is 20 m².
How do I calculate square meters from feet?
Multiply each side by 0.3048, then multiply: a 12 by 15 foot room is 16.72 m².
How big is a 24 m² room?
About 258 square feet, for example 4 by 6 m, or about 13 by 20 feet.
How big is a 20 m² room?
About 215 square feet, for example 4 by 5 m, or about 13 by 16 feet. That holds a queen bed with 30 inches clear on each side plus a dresser, which takes a 10 by 12 foot room (about 11 m²), and it is just over the 200 square feet a living room needs before a sofa, two chairs and a coffee table can stand clear of the walls.
What does m2 mean?
Square meter, also written m², sq m or sqm. It's about 10.76 square feet.
How many square meters is a hectare?
10,000, a square 100 m on each side, or about 2.47 acres; see the acres to hectares converter.