What this calculator does
Helium balloon lift works out how many balloons of a given size are needed to lift a payload. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaLift (g/L) = density of air − density of gas; balloon volume = (4/3)πr³; balloons needed = payload ÷ (volume × lift)
The inputs explained
| Field | What to enter |
|---|---|
| Weight to lift (g) | A number, measured in g. Starts at 500. |
| Balloon diameter (in) | A number, measured in in. Starts at 11. |
| Gas | Choose from Helium (1.0715 g/L lift), Hydrogen (1.0785 g/L lift). |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with weight to lift
Every other input is held at the calculator’s starting values while weight to lift varies. Select any row to load that scenario into the calculator.