Volume of a Frustum Calculator
🧊 Volume & surface area (3D). Use the Volume of a frustum formula to find volume, height, bottom radius r, top radius r: pick the value you want, type the others, and the answer updates as you go.
A cone with its top cut off: R and r are the radii of the two ends.
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| Volume | cm³ |
| Height | cm |
| Bottom radius R | cm |
| Top radius r | cm |
Worked example
Find the volume when Height = 8 cm, Bottom radius R = 6 cm, Top radius r = 3 cm.
Using V = 1/3π h (R² + Rr + r²): Volume = 527.79 cm³.
Frequently asked questions
What is the formula for Volume of a frustum?
V = 1/3π h (R² + Rr + r²). A cone with its top cut off: R and r are the radii of the two ends.
What do the letters stand for, and what units are used?
Volume in cm³, Height in cm, Bottom radius R in cm, Top radius r in cm.
How do you calculate volume?
Put the values into V = 1/3π h (R² + Rr + r²). For example, with Height = 8 cm, Bottom radius R = 6 cm, Top radius r = 3 cm, volume = 527.79 cm³.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (volume, height, bottom radius r, top radius r) and fill in the others: it rearranges the formula for you.
