Barrel Volume Calculator
Kepler devised this approximation for gauging wine casks. Because the middle bulges, the barrel holds more than a cylinder: the bulge diameter counts twice and the head diameter once.
Your numbers
Litres
228.55L
Water weight
228.6kg
Volume
228,551cm³
Formula
Volume = π × Height × (2 × Diameter² + Small circle diameter²) ÷ 12
Use it for casks, water butts and curved planters. For a straight-sided drum the cylinder calculator is more exact.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Diameter (cm)The longest line across a circle — twice the radius. | 60 | 0 and up |
| Small circle diameter (cm)The diameter of the small circles being packed in. | 50 | 0 and up |
| Height (cm)The perpendicular height from the base — not the slanted side. | 90 | 0 and up |
Step by step
Quick reference table
Results when only Diameter (cm) changes and everything else stays put.
| Diameter (cm) | Litres (L) | Water weight (kg) | Volume (cm³) |
|---|---|---|---|
| 30 | 101.32 | 101.3 | 101,316 |
| 45 | 154.33 | 154.3 | 154,331 |
| 60 | 228.55 | 228.6 | 228,551 |
| 90 | 440.61 | 440.6 | 440,608 |
| 120 | 737.49 | 737.5 | 737,489 |
What each result means
| Result | At default values |
|---|---|
| Litres (L)Capacity in litres; one litre is 1,000 cm³. | 228.55 |
| Water weight (kg)The weight of the water inside; a litre weighs a kilogram. | 228.6 |
| Volume (cm³)The space a solid holds — length cubed. | 228,551 |
Common mistakes
Use it for casks, water butts and curved planters. For a straight-sided drum the cylinder calculator is more exact.
Glossary
- Diameter
- The longest line across a circle — twice the radius.
- Small circle diameter
- The diameter of the small circles being packed in.
- Height
- The perpendicular height from the base — not the slanted side.
- Litres
- Capacity in litres; one litre is 1,000 cm³.
- Water weight
- The weight of the water inside; a litre weighs a kilogram.
- Volume
- The space a solid holds — length cubed.
Frequently asked questions
Q. How is Barrel Volume Calculator calculated?
Volume = π × Height × (2 × Diameter² + Small circle diameter²) ÷ 12 — Kepler devised this approximation for gauging wine casks. Because the middle bulges, the barrel holds more than a cylinder: the bulge diameter counts twice and the head diameter once.
Q. Can you walk through an example?
With Diameter 60cm, Small circle diameter 50cm, Height 90cm, the answer is Litres 228.55L.
Q. What do I need to enter?
Enter Diameter, Small circle diameter, Height. The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only Diameter (cm) moves the answer to Diameter (cm) 30 → Litres (L) 101.32 and Diameter (cm) 120 → Litres (L) 737.49. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
Use it for casks, water butts and curved planters. For a straight-sided drum the cylinder calculator is more exact.
Related calculators
Keep your length units consistent across inputs — mixing centimetres and metres throws results far off.