Calculate the area of seven common shapes—rectangle, triangle, trapezoid, circle, sector, ellipse, and parallelogram—with instant unit conversions.
Rectangle
Area = length × width
Area result
Formula
How to Calculate
Examples
About this calculator
The Room Area Calculator finds the area of seven common shapes—rectangle, triangle, trapezoid, circle, sector, ellipse, and parallelogram. Enter dimensions in feet, meters, or other length units and see results converted to sq ft, m², sq yd, acres, and more.
Seven shape modes
Switch between rectangle, triangle, trapezoid, circle, sector, ellipse, and parallelogram—each with a standard area formula.
Flexible length units
Measure in feet, yards, inches, miles, meters, kilometers, or centimeters. All shapes use the same unit selector for quick room and land estimates.
Instant area conversions
Results update live in square feet, square meters, square yards, square inches, acres, and hectares—ideal for flooring, paint, and property planning.
- Irregular room layouts
- Land & plot sizing
- Flooring estimates
- Geometry homework
Frequently asked questions
Quick answers about this calculator—how it works, accuracy, and everyday use.
For a rectangular room, multiply length × width. For other layouts, choose the matching shape—triangle, trapezoid, circle, and more—and enter the dimensions shown. Complex rooms can often be split into simple shapes and added together.
Rectangle, triangle (Heron's formula from three edges), trapezoid, circle, circular sector, ellipse, and parallelogram—seven common room and floor layouts.
Yes. Select meters, centimeters, kilometers, or any supported length unit from the unit menu. Area results are converted automatically to sq ft, m², sq yd, acres, and other common area units.
This tool uses Heron's formula: s = (a+b+c)/2, then area = √s(s−a)(s−b)(s−c). The three edges must satisfy the triangle inequality (each side must be shorter than the sum of the other two).