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How-to guide

How to Calculate Cone Frustum Volume: Formula, Steps & Examples

Learn how to calculate Cone Frustum Volume — the formula explained step by step, with worked examples and a free calculator to check your answer.

By Vikram Iyer, M.Sc Mathematics · Updated Jun 2026 · 2 min read

Calculating your volume is straightforward once you know the Cone Frustum Volume formula and what each input means. This guide explains the method in plain language, walks through a manual calculation, and gives worked examples you can follow — then you can do it instantly with the Cone Frustum Volume Calculator.

What is Cone Frustum Volume?

The Cone Frustum Volume calculation tells you your volume from a few simple inputs. The figure you are solving for here is the volume.

The Cone Frustum Volume formula

The core formula is:

Volume = 1 ÷ 3 × 3.141592653589793 × Height × (Bottom radius (R) ^ 2 + Bottom radius (R) × Top radius (r) + Top radius (r) ^ 2)

Here is what each input means:

  • Bottom radius (R) — a value measured in units. Example: 5 units.
  • Top radius (r) — a value measured in units. Example: 3 units.
  • Height — a value measured in units. Example: 10 units.

How to calculate it step by step

  • Write down the bottom radius (r) (for example, 5 units).
  • Write down the top radius (r) (for example, 3 units).
  • Write down the height (for example, 10 units).
  • Apply the formula above to get your volume.
  • Double-check the result with the Cone Frustum Volume Calculator.

Worked examples

Example 1

Input / OutputValue
Bottom radius (R)5 units
Top radius (r)3 units
Height10 units
Volume513.1268

With bottom radius (r) of 5 units, top radius (r) of 3 units and height of 10 units, the volume works out to 513.1268.

Example 2

With bottom radius (r) of 10 units, top radius (r) of 3 units and height of 10 units, the volume works out to 1,455.6046.

ResultValue
Volume1,455.6046

Example 3

With bottom radius (r) of 2.5 units, top radius (r) of 3 units and height of 10 units, the volume works out to 238.2374.

ResultValue
Volume238.2374

Tips for an accurate result

  • Keep your units consistent — mixing, say, months with years or grams with kilograms is the most common source of error.
  • Round only at the very end. Rounding inputs early can shift the final answer noticeably.
  • Re-run the numbers whenever an input changes, rather than estimating from an old result.

Prefer not to do the maths by hand? — the Cone Frustum Volume Calculator does it instantly, for free, with the formula and a worked example built in.

Continue exploring math calculators with these tools: Margin of Error Calculator, Sample Size Calculator, Confidence Interval Calculator, Coefficient of Variation Calculator, Regular Heptagon Area Calculator.

Calculators in this guide

Frequently asked questions

The formula is: Volume = 1 ÷ 3 × 3.141592653589793 × Height × (Bottom radius (R) ^ 2 + Bottom radius (R) × Top radius (r) + Top radius (r) ^ 2). With bottom radius (r) of 5 units, top radius (r) of 3 units and height of 10 units, the volume works out to 513.1268.

Gather each input, apply the formula step by step keeping your units consistent, and round only at the end. You can verify your answer instantly with the Cone Frustum Volume Calculator.

It uses the standard formula with exact arithmetic, so the result is correct for the inputs you enter. Bear in mind that real-world outcomes can still differ when underlying assumptions change.

Vikram Iyer · M.Sc Mathematics

Vikram Iyer is a mathematics educator with over fifteen years of teaching experience, specialising in making quantitative concepts clear and practical for everyday use.