How much helium do I need?
Pick a balloon size, set how many you are filling, and we will tell you which cylinder covers it.
Fill calculator
How much gas do you need?
You need
1.80m³ of helium
Smallest cylinder that covers it
X-Small Cylinder
1.81m³ · fills 201 · £155.71
Leaves you 1 balloon spare, which is the margin you want if anything gets over-inflated.
See this cylinderBased on filling each balloon to its proper shape. Over-inflating uses noticeably more gas, so if you are new to it, work to the figure above rather than to the balloon's maximum size.
Helium per balloon
| Balloon | Helium |
|---|---|
| 9" latex | 0.0065m³ |
| 10" latex | 0.009m³ |
| 12" latex | 0.0158m³ |
| 18" foil | 0.015m³ |
| 2ft giant | 0.1111m³ |
| 3ft giant | 0.2266m³ |
Where people go wrong
The commonest mistake is buying for the balloon count without checking the size. A 12 inch latex takes nearly two and a half times the gas of a 9 inch, for a balloon that only looks a bit bigger.
The second is over-inflating, which can cut a cylinder's real-world yield by a fifth. The third is forgetting the giants — two 3ft balloons use 0.45m³ before you have filled a single small one.
If you are close to a boundary, buy the next size up. Running out halfway through decorating a venue costs more in stress than the difference in cylinder price.