Helium Cost Per Balloon: Fill Volumes and How to Work Out Yours
Helium is one of the few materials that quietly eats your profit, because most of us never actually work out what a single filled balloon costs. Once you know the fill volume of each size and your own cost per litre, costing helium takes seconds — and you stop giving gas away for free.
Every size needs a different amount of helium
The amount of gas a balloon swallows depends on its size and whether it's latex or foil — and the differences are bigger than most people expect. A small party latex needs just a few litres, a standard 11" latex takes several times that, and a single 3ft giant can drink hundreds of litres — more than a whole bag of small balloons put together.
That spread is exactly why guessing doesn't work: price every balloon as if it were "about the same" and the big statement pieces quietly eat your margin.
Helium fill volumes by balloon size
These are the volumes to work to. They are the starting point for every helium cost you will ever calculate — and they only apply to balloons you are floating, not to air-filled work.
Latex balloons
| Size | Helium needed |
|---|---|
| 5" | 2 litres |
| 9" | 7 litres |
| 11" | 15 litres |
| 16" | 42 litres |
| 24" | 142 litres |
| 36" | 425 litres |
Foil balloons
| Size | Helium needed |
|---|---|
| 11" | 13 litres |
| 16" | 15 litres |
| 24" | 40 litres |
| 36" | 110 litres |
Two things in those tables catch most people out. A single 36" latex swallows more gas than two hundred 5" balloons — so one giant balloon thrown in as a freebie can cost more than the entire bag of smalls it sits next to. And foil is far thriftier than latex at the same nominal size: a 24" foil takes barely a quarter of what a 24" latex does, because a flat foil shape simply holds less than a sphere.
That is why "about the same" pricing quietly bleeds money. The spread between your cheapest and dearest balloon is not a few percent — it is more than two hundredfold.
Working out your cost per balloon
Two steps. First, find your cost per litre; then multiply by the balloon's fill volume.
This is the easy cost. The hard part is the other five.
Helium is one line in a quote, and it's the line with a formula you can do on your phone. What nobody does by hand is everything around it: mixed sizes across a full order, materials, your hours, overheads, delivery, margin — and a customer waiting on a number.
Quote Your Balloons costs the gas for every size automatically and rolls it into the finished quote alongside the rest. Fill a whole arch or bouquet order and the helium alone can quietly run to tens of pounds before a single balloon is counted — that's the number people forget to charge for, and the one a quote should never be missing.
How many balloons will my tank fill?
Flip the maths: divide your tank's litres by the fill volume of the size you're using. The answer surprises most people — a tank that fills a big batch of small balloons manages only a handful of the large ones. Big balloons are deceptively thirsty, and it's why quoting a giant balloon at "a bit more" than a standard one loses money.
Common helium questions
How much does it cost to fill a balloon with helium?
There's no single figure, because it depends on two things that are personal to you: what you paid for your gas, and how big the balloon is. Work out your cost per litre, multiply by that size's fill volume, and you have a real number rather than a guess. The same balloon can cost wildly different amounts to two businesses buying from different suppliers — which is why borrowing someone else's figure off a Facebook group is the fastest way to underprice.
How much does helium cost?
Cylinder prices move around a lot depending on your supplier, the tank size, and whether you own the cylinder or hire it — and hire charges and deposits are easy to forget when you're costing a job. Rather than chase a national average, use the number on your own last invoice. Divide what you actually paid by the litres in the tank and you've got the only helium price that matters for your quotes.
How much helium do I need for 100 balloons?
Multiply the fill volume of the size you're using by 100. A hundred 11" latex balloons need 1,500 litres; a hundred 5" balloons need just 200 litres; a hundred 24" latex need 14,200 litres — which is more gas than most balloon businesses keep on the premises. Be careful about which size you assume, because that's where big orders go wrong. A hundred small balloons and a hundred large ones are completely different amounts of gas, and an order that mixes sizes needs each size worked out separately and added up. For a large order it's well worth checking the total against your tank capacity before you quote, so you're not buying an extra cylinder out of your own margin.
Does helium cost need to go in every quote?
Yes — and it's the cost most often left out. Materials get counted because you can hold them; gas doesn't, because it's already paid for and sitting in the corner. Treating the tank as a sunk cost rather than a per-balloon cost is exactly how a busy month turns into a disappointing one.
Helium is one line. Quote the whole job.
Materials, labour, overheads, delivery, margin and the gas — worked out per size, totalled for the order, and turned into a branded PDF your customer can say yes to.
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