Calculate hydrogen lift from volume or find the hydrogen volume needed for a given net buoyant force in standard or custom air conditions.
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Build your own version. Describe what you want changed, added, or compared.
Hydrogen Lift Formula
The hydrogen lift calculator uses buoyancy based on the density difference between air and hydrogen.
For the standard air mode, the calculator uses:
For the custom air mode, the calculator estimates the density difference from temperature and pressure:
- F = hydrogen lift force, in newtons
- V = hydrogen volume, in cubic meters
- Δρ = density difference between air and hydrogen, in kg/m³
- g = standard gravity, 9.80665 m/s²
- P = air pressure, in pascals
- T = air temperature, in kelvin
- Mair = molar mass of dry air, 0.0289647 kg/mol
- MH2 = molar mass of hydrogen, 0.00201588 kg/mol
- R = ideal gas constant, 8.314462618 J/(mol·K)
If you enter volume, the calculator solves for lift force using F = VΔρg. If you enter lift force, it solves for required volume using V = F/(Δρg). Standard air mode uses a fixed density difference. Custom air mode calculates the density difference from the air temperature and pressure you enter.
Typical Hydrogen Lift Values
These values use the standard air setting with Δρ = 1.202 kg/m³.
| Hydrogen volume | Lift force | Mass equivalent | Approx. lbf |
|---|---|---|---|
| 1 liter | 0.01179 N | 1.202 g | 0.00265 lbf |
| 1 ft³ | 0.3338 N | 34.0 g | 0.0750 lbf |
| 1 m³ | 11.79 N | 1.202 kg | 2.65 lbf |
| 10 m³ | 117.88 N | 12.02 kg | 26.5 lbf |
| Air condition | Approx. Δρ | Lift per 1 m³ |
|---|---|---|
| 0°C, 101.325 kPa | 1.202 kg/m³ | 11.79 N |
| 15°C, 101.325 kPa | 1.140 kg/m³ | 11.18 N |
| 25°C, 101.325 kPa | 1.101 kg/m³ | 10.80 N |
| 15°C, 90 kPa | 1.012 kg/m³ | 9.93 N |
Hydrogen Lift Examples
Example 1: Find lift from hydrogen volume
You have 10 m³ of hydrogen and use the standard air setting.
The lift is about 117.88 N, equal to about 26.5 lbf or 12.02 kg mass equivalent.
Example 2: Find volume from required lift
You need 50 N of lift at 25°C and 101.325 kPa. In custom air mode, Δρ is about 1.101 kg/m³.
You need about 4.63 m³ of hydrogen.
Hydrogen Lift FAQ
Is hydrogen lift the same as payload capacity?
No. The result is the buoyant lift from the hydrogen volume after accounting for the weight of the hydrogen gas itself. To estimate payload capacity, subtract the mass or weight of the balloon envelope, frame, lines, fittings, and any required safety margin.
Why does custom air mode give a different result than standard air mode?
Standard air mode uses a fixed density difference of 1.202 kg/m³. Custom air mode calculates the density difference from temperature and pressure. Warmer air and lower pressure reduce air density, so the same hydrogen volume produces less lift.
Does humidity affect hydrogen lift?
Yes, humidity can slightly change air density. This calculator uses dry air in the custom density formula. For most rough estimates, temperature and pressure have a larger effect than humidity.
