Geometry Calculator
Choose a flat shape or solid and enter its dimensions in one unit. Get paired results such as area and perimeter, or volume and surface area, with the formulas used for each.
Enter your values or load an example. Calculations stay in this browser.
Choose the shape and the measurements you know
A rectangle needs length and width; a three-side triangle needs all three sides; circles and round solids use a radius. The form changes with your shape, and impossible three-side triangles are rejected.
Match units before calculating
Every dimension in a calculation uses the selected length unit. Area is reported in square units and volume in cubic units. A centimetre measurement combined with a metre measurement must be converted before entry.
Distinguish surface area from volume
A solid’s surface area measures its outside boundary; its volume measures enclosed space. The cylinder includes two ends, and the cone includes its circular base. Height is perpendicular to the base, not a sloping side.
Continue with a shape-specific tool
Use the dedicated area, volume and triangle tools for their additional input methods and explanations. This page provides common paired measurements; it does not infer a shape from a drawing or solve an arbitrary geometry proof.
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Frequently Asked Questions
Is circle input radius or diameter?
It is radius. Divide a diameter by two before entering it.
Does the cone include its base?
Yes. Surface area includes the circular base plus the curved side. Enter the perpendicular height.
Why are some triangle sides rejected?
The two shorter sides must add to more than the longest side. Equal totals describe a flat, degenerate figure.
Does this solve from a photo?
No. Enter numerical dimensions. The app is a separate destination for additional geometry help.
Continue in the app
Use Geometry AI - Math Solver for the full guided result after this quick check.
