Geometry

Conical Frustum Calculator

Conical frustum properties. Free online Conical Frustum Calculator. Calculate conical frustum online — fast, accurate, mobile-friendly, no signup needed.

Volume
1,350.884841

Derivation

  1. ├── 01GivenR = 8, r = 5, h = 10
  2. ├── 02Formulaπ × n / 3 × (t²+t × a+a²)
  3. └── 03Compute Volume1,350.884841
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§01What is

Understanding the Conical Frustum Calculator

The Conical Frustum Calculator computes Volume from 3 inputs: bottom radius, top radius, height. Conical frustum properties.

Geometry is what turns raw measurements into useful answers about space — how much paint, how big a yard, how much material a project will need. Every craftsperson, architect, and DIYer reaches for these formulas regularly. The Conical Frustum Calculator sits in that toolkit — it conical frustum properties. Enter your numbers above and the result updates instantly; every step of the math is shown in the Derivation panel so you can see exactly how the answer was reached.

§02The Formula

How it’s calculated

π × n / 3 × (t²+t × a+a²)

Where

R
Bottom radius
r
Top radius
h
Height
§03Practical Example

Step-by-step walkthrough

Scenario

Apply the formula to a realistic set of inputs: Bottom radius = 8, Top radius = 5, Height = 10.

  1. 01Start by noting the input — Bottom radius: 8.
  2. 02Start by noting the input — Top radius: 5.
  3. 03Start by noting the input — Height: 10.
  4. 04Substitute these values into the formula: π × n / 3 × (t²+t × a+a²)
  5. 05Compute Volume: the calculator returns 1350.88.
  6. 06Cross-check the answer by opening the Derivation panel above — every line of math is shown so you can follow the computation end-to-end.
§04Variants

Common Conical Frustum Problems

The formula gets rearranged depending on which variable you need. Here are the patterns you’ll run into in the real world — find the one that matches your problem and follow the worked steps.

01 · PATTERN

Bottom radius halved

R = 4 (from 8)

Keep every other input at its default and halve the bottom radius. See how volume responds.

  1. 01New Bottom radius: 4
  2. 02Baseline Volume: 1350.88
  3. 03New Volume: 638.791
  4. 04Volume decreases by 52.7% → use this sensitivity to plan for real-world variation.
02 · PATTERN

Bottom radius doubled

R = 16 (from 8)

Keep every other input at its default and double the bottom radius. See how volume responds.

  1. 01New Bottom radius: 16
  2. 02Baseline Volume: 1350.88
  3. 03New Volume: 3780.38
  4. 04Volume increases by 179.8% → use this sensitivity to plan for real-world variation.
03 · PATTERN

Top radius halved

r = 2.5 (from 5)

Keep every other input at its default and halve the top radius. See how volume responds.

  1. 01New Top radius: 2.5
  2. 02Baseline Volume: 1350.88
  3. 03New Volume: 945.096
  4. 04Volume decreases by 30% → use this sensitivity to plan for real-world variation.
04 · PATTERN

Top radius doubled

r = 10 (from 5)

Keep every other input at its default and double the top radius. See how volume responds.

  1. 01New Top radius: 10
  2. 02Baseline Volume: 1350.88
  3. 03New Volume: 2555.16
  4. 04Volume increases by 89.1% → use this sensitivity to plan for real-world variation.
§05FAQ

Frequently asked questions

Yes. The calculator implements the standard formula as documented and returns exact floating-point results. No approximations are used unless noted in the formula.
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