About the Area Calculator
What is the Area Calculator?
Area is the amount of flat surface a shape covers, measured in square units such as m², cm² or square feet. You need it for flooring, painting, tiling, plot and land sizes, fabric, and seed or fertiliser quantities.
Choose one of ten shapes, enter its dimensions and pick your length unit. The calculator returns the area in that unit squared, the perimeter where the dimensions allow it, and conversions to square metres and square feet — handy because property sizes in India are usually quoted in sq ft.
How to use the Area Calculator
- Shape — each option lists which dimensions it uses. (sample: Rectangle (length a, width b))
- Dimension a (sample: 12)
- Dimension b (sample: 10)
- Dimension c (trapezoid height or third side) (sample: 8)
- Length Unit — all dimensions must be in this unit. (sample: Metres)
- Press Calculate Area (results also refresh as you type). The result card shows the Area, along with Perimeter and Area in square feet.
Formula used
Rectangle A = l × w | Circle A = πr² | Triangle A = ½ × b × h
- Triangle (3 sides) = Heron's formula √(s(s − a)(s − b)(s − c)), with s = (a + b + c) ÷ 2
- Trapezoid = ½ × (a + b) × h
- Ellipse = π × a × b
- Rhombus = ½ × d₁ × d₂
- Sector = πr² × θ ÷ 360
The ellipse perimeter uses Ramanujan's approximation, which is accurate to a tiny fraction of a percent for everyday shapes.
Worked example
These are the sample values already filled in the calculator above, and the result it returns for them:
| Input | Sample value |
|---|---|
| Shape | Rectangle (length a, width b) |
| Dimension a | 12 |
| Dimension b | 10 |
| Dimension c (trapezoid height or third side) | 8 |
| Length Unit | Metres |
| Result | Value |
|---|---|
| Area | 120 m² |
| Perimeter | 44 m |
| Area in square feet | 1,291.6693 ft² |
Area unit conversions
| Unit | Equivalent |
|---|---|
| 1 square metre | 10.7639 sq ft |
| 1 square foot | 0.092903 m² (144 sq in) |
| 1 square yard | 9 sq ft = 0.836127 m² |
| 1 acre | 43,560 sq ft = 4,046.86 m² |
| 1 hectare | 10,000 m² = 2.471 acres |
Tips for using the Area Calculator
- Split an L-shaped room into two rectangles, find each area and add them.
- Add 5–10% to flooring and tile quantities to allow for cutting and breakage.
- Area grows with the square of length: doubling every side makes the area four times larger.