Helium is lighter than air, so each litre of helium pushes upward with about one gram of force. A standard 11-inch party balloon holds about 11 litres and can lift roughly 11 g, but the latex itself weighs about 3 g, leaving 8 g. That means lifting an average adult would take thousands of balloons.
How to use the Helium Balloons Calculator
- Weight to lift
- Balloon size
- Gas
- Weight of one empty balloon
Results update as you type, and every field accepts the units shown in its menu.
How it works
Enter the weight to lift, choose the balloon size and gas, and the weight of one empty balloon.
Tips
- Results are estimates meant for planning and fun – adjust the inputs to match your situation.
- Everything runs in your browser, so you can try as many variations as you like.
- Share the result link with friends so everyone sees the same numbers.
- For safety-related hobbies (hammocks, balloons, tents), follow the manufacturer’s limits.
Common mistakes to avoid
- Using default values when you know your own figures.
- Treating rough rules of thumb as exact.
- Forgetting to add breaks, travel or setup time.
Inputs explained
| Field | What to enter |
|---|---|
| Weight to lift | Units: kg, lb, g |
| Balloon size | Choose one: 5 in (mini), 9 in, 11 in (standard), 16 in … |
| Gas | Choose one: Helium (≈ 1.05 g/L), Hydrogen (≈ 1.11 g/L), Methane (≈ 0.54 g/L), Ammonia (≈ 0.48 g/L) |
| Weight of one empty balloon | In g |
What each result means
- Volume of one balloon = pi÷6×[Balloon size]^3
- Net lift per balloon = [Gas]×[Volume of one balloon]×1000 – [Weight of one empty balloon]
- Gas needed = [Balloons needed]×[Volume of one balloon]
Example values
How the main result changes when Weight to lift changes and everything else stays at the example values above:
| Weight to lift (kg) | Balloons needed |
|---|---|
| 35 | 3,893 |
| 52.5 | 5,839 |
| 70 | 7,786 |
| 87.5 | 9,732 |
| 105 | 11,678 |
| 140 | 15,571 |
Formula
Net lift per balloon = gas lift × volume − balloon weightVolume = π ÷ 6 × diameter³Balloons needed = weight ÷ net lift per balloonHelium lifts ≈ 1.05 g per litre at sea levelWorked example
Inputs — Weight to lift: 70 kg; Balloon size: 11 in (standard); Gas: Helium (≈ 1.05 g/L); Weight of one empty balloon: 3 g.
Results — Volume of one balloon = 11.4 L; Net lift per balloon = 9 g; Balloons needed = 7,786; Gas needed = 88.9 m³.
Frequently asked questions
How many balloons to lift a person?
About 9,000 standard 11-inch helium balloons for a 70 kg adult – far more than in the film "Up".
How much can one helium balloon lift?
An 11-inch latex balloon lifts about 8 g after its own weight.
Why does helium lift?
Helium is about seven times less dense than air, so the surrounding air pushes it upward (buoyancy).
What formula does the Helium Balloons Calculator use?
Net lift per balloon = gas lift × volume − balloon weight.