Cone volume and surface area calculator
Enter the base radius and perpendicular height of a cone to get its volume and areas.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter base radius, height and length unit.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Volume = 1/3 × π × r² × h, slant height s = √(r² + h²), lateral area = πrs, total area = πrs + πr².
Example
Inputs: Base radius = 3, Height = 4, Length unit = Centimeter (cm). Result: Volume: 37.6991 cm³; Slant height: 5 cm; Lateral surface area: 47.1239 cm².
Limits and caveats
- Covers right circular cones only, with the apex directly above the base center.
- Results are in the cube or square of the unit you chose, so enter every dimension in that same unit.
Questions about this tool
What is the cone volume formula?
Volume is one third of base area × height: 1/3 × π × r² × h.
What is height versus slant height?
Height runs straight down from the apex to the base center. Slant height runs along the surface from apex to base edge.
What if I know the slant height instead?
Find the height first with h = √(s² − r²), then enter it. A slant of 5 with radius 3 gives height 4.