Square Meters Calculator
Get an area in square meters from any tape measure. Choose rectangle, circle, or triangle, enter dimensions in meters, feet, or centimeters, and see the area in m², square feet, and square yards.
Example: with Shape Rectangle (length × width) · Length / diameter / base 5 · Width / height 4 · Dimensions are in meters → Area: 20.00 m2.
- In square feet215.28 sq ft
- In square yards23.92 sq yd
Computed by the calculator below using its default values. Change any input to see your own numbers.
Area formulas in meters: rectangle L × W, circle π × (d/2)², triangle b × h ÷ 2. One square meter equals 10.7639 square feet.
Square meters, and getting there from feet
A square meter is the area of a 1 m × 1 m square — the standard for floor plans, apartment listings, and materials almost everywhere outside the US. The conversion pivot is exact: 1 foot is defined as 0.3048 m, so one square foot is 0.09290304 m² and one square meter is 10.7639 sq ft. A quick sanity check: multiply square meters by about 10.8 to picture the space in square feet.
For odd rooms, split the floor into rectangles and triangles, calculate each, and add them. Measure in whatever unit your tape shows — the calculator converts feet or centimeters to meters before squaring, which avoids the classic error of converting after squaring (the factor is 10.76, not 3.28, once units are squared).
How it’s calculated
Dimensions are converted to meters first (1 ft = 0.3048 m exactly; 1 cm = 0.01 m), then: rectangle = L × W; circle = π × (diameter ÷ 2)²; triangle = base × height ÷ 2. Conversions out: 1 m² = 10.7639104 sq ft = 1.19599005 sq yd (NIST factors).
Treats surfaces as flat — sloped ceilings, curved walls, and bay bump-outs need to be measured as separate pieces and added.
Quick m² to sq ft references
| Square meters | Square feet | About the size of |
|---|---|---|
| 1 m² | 10.8 sq ft | A small dining table |
| 10 m² | 108 sq ft | A compact bedroom |
| 20 m² | 215 sq ft | A studio's main room |
| 50 m² | 538 sq ft | A one-bedroom apartment |
| 100 m² | 1,076 sq ft | A modest single-family home |
Computed at 1 m² = 10.7639 sq ft; size comparisons are typical, not definitions.
Common mistakes
- Multiplying feet dimensions and then dividing by 3.28 — squared units need the squared factor, 10.76.
- Entering a circle's diameter where the formula expects radius (this tool takes diameter and halves it for you).
- Mixing units in one entry, like meters for length and feet for width.
- Measuring wall-to-wall but quoting the tiled or carpeted area, which excludes fixtures and alcoves.
Frequently asked questions
How do I calculate square meters?
Multiply length by width, both in meters: a 5 m by 4 m room is 20 m². For circles use π × (diameter ÷ 2)², and for triangles base × height ÷ 2.
How many square feet is a square meter?
10.7639 square feet. The factor comes from the exact definition 1 ft = 0.3048 m: (1 ÷ 0.3048)² = 10.7639.
How do I convert square feet to square meters?
Multiply by 0.0929 (exactly 0.09290304). A 120 sq ft room is 120 × 0.0929 = 11.15 m².
Why is my converted area wrong by a factor of three?
Almost always from using the linear factor (3.28 ft per m) on an area. Areas scale with the square of length, so the right factor is 3.28² = 10.76.