How to use this square footage calculator
- Choose the shape of the area: rectangle, circle or triangle.
- Pick your unit (feet, inches, yards, metres or centimetres) and enter the measurements.
- If the space has several parts, like an L-shaped room or a house with many rooms, click Add another area for each part. Use Qty when you have identical areas, such as three bedrooms of the same size.
- Optionally add a waste % and a price to see how much material to buy and what it will cost.
Square footage formulas
Area is always length × width for a rectangle. The calculator converts every measurement to the same unit first, so you can mix feet and inches across different areas.
Circle: Area = π × (Diameter ÷ 2)²
Triangle: Area = (Base × Height) ÷ 2
Worked example
A living room measures 14 ft by 12 ft and has a 6 ft by 4 ft alcove.
- Main room: 14 × 12 = 168 sq ft
- Alcove: 6 × 4 = 24 sq ft
- Total: 168 + 24 = 192 sq ft (about 17.84 m²)
- With 10% waste for laminate flooring: 192 × 1.10 = 211.2 sq ft to buy
Ready to buy materials? The flooring calculator turns your area into boxes of laminate, vinyl or hardwood, and the tile calculator into tiles and boxes.
How to measure a room accurately
- Measure wall to wall at floor level with a tape measure or laser measure. Walls are rarely perfectly straight, so measure in two places and use the larger number.
- Round up to the nearest inch or centimetre. Small rounding errors add up across a whole house.
- Split odd shapes into simple ones. An L-shaped room is two rectangles. A room with a bay window is a rectangle plus a small rectangle or triangle.
- Subtract what you won’t cover. For flooring, you can skip fixed kitchen islands. For paint, you need wall area, not floor area, which our paint calculator works out for you.
- Write measurements down as you go, with a quick sketch of the room. It saves a second trip.
Area unit conversions
| From | To | Multiply by |
|---|---|---|
| Square feet | Square metres | 0.0929 |
| Square metres | Square feet | 10.764 |
| Square feet | Square yards | 0.1111 (÷ 9) |
| Square yards | Square feet | 9 |
| Square inches | Square feet | 0.00694 (÷ 144) |
| Acres | Square feet | 43,560 |
Typical room sizes
Use these as a rough guide when you plan a budget before measuring. Real rooms vary a lot.
| Room | Example size | Area |
|---|---|---|
| Small bedroom | 10 × 10 ft | 100 sq ft (9.3 m²) |
| Main bedroom | 12 × 14 ft | 168 sq ft (15.6 m²) |
| Living room | 16 × 20 ft | 320 sq ft (29.7 m²) |
| Kitchen | 10 × 12 ft | 120 sq ft (11.1 m²) |
| Bathroom | 5 × 8 ft | 40 sq ft (3.7 m²) |
| One-car garage | 12 × 22 ft | 264 sq ft (24.5 m²) |
Frequently asked questions
How many square feet is a 12x12 room?
A 12 ft by 12 ft room is 144 square feet (12 × 12 = 144), which is about 13.4 m². If you are buying flooring, add 5–10% for cutting waste, so plan on roughly 151–158 sq ft of material.
How do I calculate square footage of an L-shaped room?
Split the room into two rectangles, measure each one, and add the two areas together. Use the “Add another area” button above to enter each rectangle separately and the calculator adds them for you.
How do I convert square feet to square metres?
Divide square feet by 10.764 to get square metres. To go the other way, multiply square metres by 10.764. For example, 200 sq ft ÷ 10.764 = 18.58 m².
How do I convert square feet to square yards?
Divide square feet by 9, because one square yard is 3 ft × 3 ft = 9 sq ft. Carpet and some turf products are still sold by the square yard.
How much extra flooring should I buy?
Most installers add 5–10% for straight layouts and 10–15% for diagonal, herringbone or heavily patterned layouts. Check the manufacturer’s recommendation for your product.
Do closets and hallways count in square footage?
For a flooring or paint job, include every area that will get the material, including closets. For property listings, the rules for what counts as living area vary by country and region, so follow your local standard.
Last reviewed November 5, 2026.