Square Footage Calculator
Material Cost Estimator (optional)
About this calculator
Calculate the area of a rectangle, triangle, circle or L-shaped room in feet, metres, centimetres or inches, then estimate flooring cost with a waste allowance.
Great for tiles, paint, carpets and plots.
How to use it
- Choose the shape and unit.
- Enter the dimensions.
- Add cost per sq ft and waste % to estimate material cost.
Area formulas
Rectangle = length × width. Triangle = ½ × base × height. Circle = π × r² (r = d ÷ 2). L-shape = big rectangle − the cut-out rectangle. 1 square metre = 10.7639 square feet. Always add 5 to 10% waste for tiles and flooring (10 to 15% for diagonal patterns).
Worked example
5 ft × 4 ft room, ₹80 per sq ft, 10% waste
| Area | 20 sq ft |
| With 10% waste | 22 sq ft |
| Cost | 22 × 80 = ₹1,760 |
Tips and common mistakes
- Measure twice, buy once.
- Round up to full boxes of tiles.
- Subtract door and window openings for paint, not for flooring.
- Keep a few spare tiles for repairs.
- Convert metres to feet by multiplying by 3.2808.
Frequently asked questions
How do I calculate square feet?
Length × width in feet.
How many sq ft in a sq metre?
10.7639.
How much waste should I add?
5 to 10% for straight lays.
How do I find a triangle's area?
½ × base × height.
How do I find an L-shape's area?
Split it into two rectangles.
Is it free?
Yes.