Barrel Volume Calculator

Work out barrel volume instantly with clear inputs, formula shown and shareable results.

About Barrel Volume Calculator

Kepler's barrel rule treats the staves as parabolic arcs and gives V = πh(2D² + d²)/12, where D is the diameter at the widest point and d at the ends.

Formula

Kepler barrel rule

V = πh(2D² + d²) / 12

Worked example

With the default values below, Barrel Volume Calculator returns Volume of 228,550.8655. Change any input above and every figure here is recalculated in your browser.

Inputs used

Diameter at the bulge Dminimum 0: 60
Diameter at the ends dminimum 0: 50
Heightminimum 0: 90

Results

Volume: 228,550.8655
Litres if dimensions are cm: 228.5509
Volume of a cylinder at the bulge diameter: 254,469.0049
Bulge depth per side: 5.0000

Step by step

1Values used
2Kepler barrel rule
3Volume= 228,550.8655
4Litres if dimensions are cm= 228.5509
5Volume of a cylinder at the bulge diameter= 254,469.0049
6Bulge depth per side= 5.0000

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

What if D = d?

The formula becomes πhD²·3/12 = πD²h/4, the plain cylinder, as expected.

How accurate is it?

For real barrels with gently curved staves it is within a percent or so; a parabolic profile makes it exact.