How to use the Area Calculator
- Pick the shape.
- Choose the unit you measured in.
- Enter the measurements.
- Read the area in square feet, square meters, square yards, acres and hectares.
Formula used
| Shape | Formula |
|---|---|
| Rectangle | l × w |
| Square | s² |
| Circle | π r² |
| Triangle | ½ b h |
| Triangle (Heron) | √(s(s−a)(s−b)(s−c)), s = (a+b+c)/2 |
| Trapezoid | ½ (a + b) h |
| Parallelogram | b × h |
| Ellipse | π a b |
| Sector | θ/360 × π r² |
1 sq m = 10.764 sq ft. 1 acre = 43,560 sq ft = 4,046.86 m². 1 hectare = 10,000 m² = 2.471 acres.
Worked examples
| Shape | Measurements | Area |
|---|---|---|
| Room | 12 × 15 ft | 180 sq ft (16.72 m²) |
| Lot | 50 × 100 ft | 5,000 sq ft (0.115 acres) |
| Circle | r = 7 m | 153.94 m² |
| Triangle | b = 10, h = 6 cm | 30 cm² |
| Garden | 4 × 6 m | 24 m² (258.33 sq ft) |
Frequently asked questions
How do I calculate square feet?
Measure length and width in feet and multiply them. A 10 ft by 12 ft room is 120 sq ft.
How many square feet are in an acre?
43,560 square feet, or about 4,047 square meters.
How do I calculate the area of an L-shaped room?
Split it into two rectangles, find each area and add them.
How do I convert square meters to square feet?
Multiply by 10.764. 100 m² is about 1,076 sq ft. The Unit Converter handles all area units.
How much flooring or paint do I need?
Work out the area, then add about 10% for waste and cuts.
Written and tested by MasterKit Online Editorial Team
Our team builds and tests every tool by hand, checks each formula against official sources (IRS, HMRC, the Income Tax Department of India, CBSE, NHS, WHO) and reviews pages whenever rules change. Last reviewed on . Spotted a mistake? Tell us.