Calculate blimp volume, length, or diameter from any two values and see the missing result in your chosen unit with m, ft, in, cm, L, ft³, or gal.

Blimp Volume Calculator

Enter any 2 values to calculate the missing variable


Related Calculators

Blimp Volume Formula

The calculator treats the blimp envelope as a prolate spheroid, which is an elongated sphere. Enter any two values, and it solves for the missing length, diameter, or volume.

V = (pi/6)*L*D^2
  • V = blimp volume
  • L = blimp length
  • D = maximum blimp diameter
  • pi = 3.14159…

To calculate the missing value, the same formula is rearranged:

L = (6*V)/(pi*D^2)
D = sqrt((6*V)/(pi*L))
  • Volume calculation: uses length and diameter to estimate the internal gas volume.
  • Length calculation: uses volume and diameter to find the required blimp length.
  • Diameter calculation: uses volume and length to find the required maximum diameter.

Common Blimp Volume Unit Conversions

Use these conversions to check results when switching between metric and U.S. customary units.

Unit Equivalent
1 cubic meter, m³ 35.3147 cubic feet
1 cubic foot, ft³ 0.0283168 cubic meters
1 cubic meter, m³ 1,000 liters
1 U.S. gallon 0.00378541 cubic meters

Typical Length-to-Diameter Ratios

The formula works for any positive length and diameter, but real blimp shapes are usually longer than they are wide.

Length ÷ Diameter Shape Description
2:1 Short, rounded envelope
3:1 Moderately elongated blimp shape
4:1 Long, slender envelope
5:1 or higher Very slender airship-style shape

Example Calculations

Example 1: Calculate blimp volume

Suppose a blimp has a length of 40 m and a maximum diameter of 10 m.

V = (pi/6)*40*10^2
V = 2094.3951 m^3

The estimated blimp volume is 2,094.3951 m³.

Example 2: Calculate blimp diameter

Suppose a blimp volume is 1,500 m³ and its length is 30 m.

D = sqrt((6*1500)/(pi*30))
D = 9.7721 m

The required maximum diameter is 9.7721 m.

FAQ

What shape does this blimp volume calculator assume?

It assumes the blimp is shaped like a prolate spheroid, which is similar to an ellipsoid stretched along its length. This is a common simplified model for estimating envelope volume. Real blimps may have fins, nose shape variations, tail taper, or other design details that make the actual volume slightly different.

Why do I only enter length and diameter?

The formula assumes the blimp is symmetric around its long axis, so one maximum diameter represents both cross-section dimensions. If the envelope is not circular in cross-section, this simplified formula will be less accurate.

Can this volume be used to estimate lifting capacity?

Yes, but only as a starting point. Lift depends on the gas used, outside air density, temperature, pressure, envelope weight, payload, and other equipment. The calculator gives the internal volume, not the final usable lift.