Math
Area Calculator
Last Updated: July 11, 2026
Calculate the area of any shape instantly. Supports rectangle, square, triangle, circle, trapezoid, parallelogram, and ellipse with results in multiple units.
Area Results
Square Feet
0 sq ft
Square Meters
0 sq m
Square Yards
0 sq yd
Acres
0 acres
Square Inches
0 sq in
How to Use This Area Calculator
- Select the shape you want to calculate: rectangle, square, triangle, circle, trapezoid, parallelogram, or ellipse.
- Choose your unit of measurement: feet, meters, inches, or yards.
- Enter the required dimensions — the form will dynamically update to show only the inputs needed for your selected shape.
- Click "Calculate Area" to see the area converted to 5 different units: sq ft, sq m, sq yd, acres, and sq in.
Area Formulas by Shape
Rectangle
A = Length × Width
Square
A = Side²
Triangle
A = (Base × Height) / 2
Circle
A = π × Radius²
Trapezoid
A = ((a + b) / 2) × h
a, b = parallel sides, h = heightParallelogram
A = Base × Height
Ellipse
A = π × a × b (where a = semi-major axis, b = semi-minor axis)
Quick Reference: Common Area Conversions
| From | To | Multiply By |
|---|---|---|
| Square Feet | Square Meters | × 0.0929 |
| Square Meters | Square Feet | × 10.764 |
| Acres | Square Feet | × 43,560 |
| Acres | Square Meters | × 4,047 |
| Square Yards | Square Feet | × 9 |
Frequently Asked Questions
Break the irregular shape into regular shapes (rectangles, triangles, circles). Calculate the area of each section using the appropriate formula, then add them together. For very complex shapes, use the grid method: overlay a grid on the shape and count the squares inside.
The area of a trapezoid is A = ((a + b) / 2) × h, where a and b are the lengths of the two parallel sides, and h is the height (perpendicular distance between the parallel sides). This is equivalent to averaging the two parallel sides and multiplying by the height.
There are exactly 43,560 square feet in one acre. For reference, a standard American football field (including end zones) is about 57,600 sq ft or 1.32 acres.
For rectangular rooms, multiply length × width. Measure in feet and the result is in square feet. For L-shaped rooms, split into two rectangles and add. For rooms with closets, add the closet area. Always add 10% extra for waste, cuts, and pattern matching.
Disclaimer
This area calculator provides results for informational and planning purposes. Accuracy depends on the precision of your input measurements. For construction or legal purposes, consult a licensed surveyor or professional. Area calculations do not account for slopes, uneven surfaces, or wall thickness.