How much helium do I need?
Enter your balloon quantities to estimate the gas volume in cubic metres (m³) for your display. Mix balloon types, add an optional allowance and compare the number of cylinders needed.
Compare cylinder quantities
Each result is an alternative using one cylinder size throughout. Quantities are rounded up to whole cylinders; do not add the different options together.
Heli Box 30
0.255 m³ approximate capacity
cylinder(s) if using this size onlyHeli Box 50
0.425 m³ approximate capacity
cylinder(s) if using this size onlyV size
1.81 m³ gas capacity
cylinder(s) if using this size onlyT size
3.60 m³ gas capacity
cylinder(s) if using this size onlyL size
9.00 m³ gas capacity
cylinder(s) if using this size onlyE33 size
8.56 m³ gas capacity
cylinder(s) if using this size onlyGENIE 10
2.60 m³ gas capacity
cylinder(s) if using this size onlyGENIE 20
5.19 m³ gas capacity
cylinder(s) if using this size onlyHeli Box 30 and 50 use approximate converted capacities of 0.255 m³ and 0.425 m³. They also use the advertised yields for 9-inch latex, 11-inch latex and 18-inch foil round balloons where available. For those sizes, the calculator takes the more conservative result. Other sizes use a gas-volume estimate. Check suitability and current product specifications before ordering, especially for large display balloons.
Plan the display before the gas
Start with your finished balloon arrangement: how many balloons are in each bunch, which sizes you will use and whether the design includes latex, foil or bubble balloons. Enter each type separately so that a few large balloons are not treated like a batch of small ones.
If your balloon size or shape is not listed, check its manufacturer's filling guidance or ask us before substituting another size. A shaped foil number and a round balloon of a similar advertised size do not necessarily take the same volume.
Disposable cylinder or hire?
Heli Box disposable cylinders offer a convenient option for smaller celebrations. A hire cylinder can be useful for larger displays, regular decorating work and events needing more gas in one cylinder.
The quantities above compare capacity, not price or availability. Check collection or delivery arrangements, filling-kit requirements and the details of your chosen product. Our team can help you interpret the results for your event.
Helium planning questions
Why does balloon size make such a difference?
The gas fills a three-dimensional space. Increasing a balloon's diameter can increase the volume substantially, so a cylinder's advertised count is meaningful only for the stated balloon size.
Can I use the calculator for a mixed display?
Yes. Enter quantities against every listed type you plan to use. The total combines their reference gas volumes, then applies your selected allowance.
Does this tell me how long the balloons will float?
No. Gas quantity and float time are different measurements. Check the balloon manufacturer's guidance and the information for your helium product when deciding when to inflate.
Which units should I compare?
All gas volumes and cylinder capacities are shown in cubic metres (m³), with the total also shown in litres. One cubic metre equals 1,000 litres. Compare it with the cylinder's stated gas capacity, rather than its physical size or pressure alone.
Reference figures
The 9-inch and 11-inch latex figures follow BOC’s balloon gas guide (PDF). The other balloon volumes are existing planning estimates converted to m³ and rounded to six decimal places. They are guides rather than guarantees for every brand or shape.
View the balloon reference table
| Balloon type | Helium volume (m³) | Estimated lift |
|---|---|---|
| 9 inch Latex Balloons | 0.007 m³ | 6 g |
| 11 inch Latex Balloons | 0.011 m³ | 10 g |
| 24 inch Round Latex Balloons | 0.141584 m³ | 120 g |
| 3 foot Round Latex Balloons | 0.424753 m³ | 340 g |
| 4 foot Chloroprene | 0.962773 m³ | 770 g |
| 5.5 foot Chloroprene | 2.463566 m³ | 2,130 g |
| 8 foot Chloroprene | 7.560598 m³ | 7,000 g |
| 22 inch Single Bubble | 0.028317 m³ | 14 g |
| 24 inch Double Bubble | 0.035396 m³ | 7 g |
| 18 inch Foil Rounds | 0.014158 m³ | 2 g |
| 36 inch Foil Rounds | 0.113267 m³ | 30 g |
| 38" Foil Number | 0.049554 m³ | 10 g |