Calculate Cone or Truncated Cone Volume and Surface Area
Calculate a full cone or frustum from radius or diameter, solve for a missing radius or height, estimate slant height, lateral and total surface area, fill volume, mass and material cost.
Geometry mode
Cone calculation result
Cone and frustum volume formulas
A full cone has volume πr²h/3. A frustum has volume πh(R² + Rr + r²)/3, where R is the base radius and r is the top radius. When the top radius is zero, the frustum formula becomes the cone formula.
Surface area and slant height
For a cone, slant height is the square root of r² + h². For a frustum, use the radius difference: √((R−r)²+h²). Lateral surface area equals π(R+r)s for a frustum.
Solving a missing dimension
Height can be isolated directly from the volume formula. Cone radius can be solved from volume and height. Frustum reverse solving is not offered unless enough dimensions are known.
Can I enter diameter instead of radius?
Yes. The calculator divides diameter by two before applying the formulas.
How do I calculate liters or gallons?
The selected length unit is converted to cubic meters internally, then to liters and US gallons.
Does fill percentage change surface area?
No. It changes the filled volume, mass and material cost, not the complete cone’s geometric surface area.