Balloon Arch Calculator
How many balloons a balloon arch or organic garland needs for its length, in the sizes you plan to use — and how much helium if it floats.
A classic spiral arch of 11-inch balloons uses about 16 balloons per metre (five per foot) in clusters of four.
How the balloon arch calculator works
A classic spiral arch of 11-inch balloons uses about 16 balloons per metre (five per foot) in clusters of four. An organic garland mixes sizes and packs tighter — roughly 25 balloons per metre, mostly 5-inch and 11-inch with a few 16-inch feature balloons. Add 10% for pops and mistakes. Helium is only needed for a floating arch; an 11-inch balloon takes about 14 litres (0.5 cu ft).
Formula: balloons = length × per-metre rate × 1.1; helium = balloons × litres per balloon
Worked examples
| Inputs | Balloons to buy | Note |
|---|---|---|
| 4 m organic garland | 110 | 110 balloons |
| 10 ft spiral arch | 54 | 54 balloons |
| 3 m floating string | 27 | 27 balloons, 378 L helium |
FAQFrequently asked questions
Helium or air?
Air, almost always: garlands and arches on a frame, wall or tape strip last for days, cost nothing to fill and hold their shape. Helium is for balloons that must float free, and it lasts under a day in latex.
How long does it take?
With an electric pump, about a minute per two balloons including tying, so a 100-balloon garland is roughly an hour for two people plus assembly. Hand pumps take three times as long.
Can I make it the day before?
Air-filled latex holds for two or three days indoors and looks fine; heat, sun and wind shorten that. Assemble at home on a strip and hang it on the day.
What sizes do I need?
Organic garlands look best with mostly 5-inch and 11-inch balloons and a few 16- or 18-inch statement balloons; a spiral arch uses one size, and 11-inch is the standard.
Where these figures come from
- US FDA Food Code — food service guidance — holding and service context behind catering quantities
- UK Food Standards Agency — the UK food regulator
Last checked: September 2026. Portion and spacing figures are standard catering and event-industry conventions, stated on each page.