Area Calculator

Work out areas for common shapes quickly. Choose a shape, enter the dimensions, and get the area. Perimeter is included where useful. You can set units and decimals, copy a share link, and export a CSV.

Shape

Units (label only)

Labels the results as unit². No conversion performed.

Decimals

Length

Width

Formula: A = L × W, P = 2(L + W)

Side

Formula: A = s², P = 4s

Radius

Formula: A = πr², C = 2πr

Base

Height

Other sides (optional, for perimeter)

Formula: A = ½ × base × height

Base 1

Base 2

Height

Formula: A = ½ × (b₁ + b₂) × h

Semi-major axis (a)

Semi-minor axis (b)

Formula: A = πab

Area

Perimeter

Status

About this calculator

This area calculator covers the most used shapes in everyday tasks and school work. It shows the formula for each shape next to the inputs so you can see how the result is produced. Perimeter is shown where it can be computed from the given dimensions without guessing missing sides.

Units here are for labelling only. If you measured in centimetres, set the unit to cm and the output will appear as cm². If you need conversions, use a converter tool first, then drop the converted number in here. Adjust the decimal places to suit your report or copy and paste into a document.

Use the share link to keep your setup or send a prefilled example. The CSV export captures your inputs and outputs for quick notes.

Explore more in the calculators hub.