Geometry Calculators

Geometry problems are easy to set up and easy to slip up on — a squared term dropped here, a unit mismatch there. The calculators in this category handle the standard shape math: area, perimeter, and the diagonal of a rectangle, with more shapes to follow. Every tool converts between metric and imperial units for you, shows the formula it used, and breaks the calculation into steps so you can follow the reasoning or check your own work. They run entirely in your browser and accept decimals wherever it makes sense. Pick the calculator that matches your shape, enter the measurements, and read off the result.