Geometry & Shapes
Cone Calculator
Cone — it uses volume = 1⁄3·πr²h, with slant height = √(r² + h²). This page runs that same calculation on your numbers, in your browser: no signup, no uploads, nothing stored.
Give Cone Calculator your radius and height and it returns the volume and surface area straight away. Built to find the volume and surface area of the solid, it runs entirely on your device.
About this calculator
It uses volume = 1⁄3·πr²h, with slant height = √(r² + h²). That is the whole of the calculation — the mistakes happen in the inputs. It matters whenever a shape has to be measured, cut, covered or compared and the geometry has to be right first. Worked example: A cone with radius 3 and height 4: volume = ⅓π × 3² × 4 = 37.7 . Use the calculator with your own figures; it runs entirely on your device.
How to use
- Enter the base radius of the cone.
- Enter the vertical height.
- Press Calculate to measure the cone.
- Read the volume, surface area, and slant height.
Why use Cone Calculator
Fast
Calculations run in your browser. No round trip to a server.
Private
Your inputs never leave your device. Nothing is uploaded.
Free
No signup, no paywall, no ads-in-results, no watermarks.
Accurate
Uses standard formulas for quick educational estimates; check critical results before relying on them.
Mobile-ready
Optimised for phones, tablets, and desktops alike.
Transparent
Honest disclaimers wherever browser limits or regional rules apply.
Common uses
Use it for 3D modelling and CAD prep
Use it for volume and capacity checks
Use it for material-volume estimates
Use it when comparing two solids
Use it for packaging and box design
Use it for quick volume and surface-area checks
Technical notes
Cone Calculator uses volume = 1⁄3·πr²h, with slant height = √(r² + h²).
Results assume exact, idealised shapes; real-world measurement error is not included.
All arithmetic runs in your browser using double-precision floating point, so extreme inputs may show tiny rounding differences.
FAQ
What is the slant height of a cone?
It is the distance from the base edge to the apex along the surface, equal to the square root of radius squared plus height squared.
How is cone volume calculated?
Cone volume is one third of the base area times the height: (1/3)πr²h.
Does the surface area include the base?
Yes. The total surface area combines the curved lateral surface and the circular base.
Does the Cone Calculator send my data to a server?
No. The Cone Calculator runs entirely in your browser, so nothing you enter is uploaded, stored, or shared.
Worked example
A cone with radius 3 and height 4: volume = ⅓π × 3² × 4 = 37.7.