Foil Balloon Sizes Chart: 12 Common Sizes, Helium Capacity and Carton Quantities

2026-10-16 · Wonabo

Three numbers decide whether a foil balloon order is profitable: the inflated size, the helium it consumes, and the carton quantity.

Get the size wrong and the balloon does not match the decoration plan. Get the helium figure wrong and your cost per bouquet is off by 20%. Get the carton quantity wrong and your freight per unit doubles.

This is the chart we send to buyers before their first order. All dimensions are inflated size — flat, un-inflated balloons measure smaller and are not a useful reference for planning.

The master chart

Size (nominal)	Inflated size	Helium per balloon	Float time (helium)	Air-filled life	Typical carton
10" / mini	~25 cm	0.13–0.16 cu ft	2–4 days	3–6 months	500 pcs
18"	~46 cm	0.45–0.55 cu ft	5–7 days	6–12 months	200 pcs
22"	~56 cm	0.65–0.75 cu ft	7–10 days	6–12 months	100 pcs
24"	~61 cm	0.85–1.0 cu ft	10–14 days	6–12 months	100 pcs
28"	~70 cm	1.4–1.6 cu ft	2–3 weeks	12+ months	50 pcs
36"	~91 cm	2.8–3.2 cu ft	2–3 weeks	12+ months	50 pcs
40"	~102 cm	3.5–4.0 cu ft	3–4 weeks	12+ months	30–50 pcs
16" number/letter	~40 cm	0.35–0.45 cu ft	5–7 days	6–12 months	200 pcs
32" number/letter	~81 cm	2.2–2.6 cu ft	2–3 weeks	12+ months	50 pcs
40" number/letter	~102 cm	3.5–4.0 cu ft	3–4 weeks	12+ months	30–50 pcs
3D / 4D shape	varies by shape	0.6–1.2 cu ft	7–14 days	6–12 months	50–100 pcs
Balloon garland strip	5 m / 16 ft strip	n/a (air-filled)	n/a	1–2 months	100 strips

Two notes that matter operationally:

Float time is measured at room temperature (20–22 °C), indoors. A 40" balloon that floats three weeks in a shop window may last ten days outdoors in summer heat, and longer in a cold climate. Temperature affects helium volume roughly 1% per 3 °C.

Air-filled life is much longer than helium life because air does not escape through the film the way helium does. A foil balloon filled with air and hung on a wall can look good for months. This is why foil balloons dominate static decoration and latex dominates floating bouquets.

How to use the chart: three worked examples

Example 1 — a helium bouquet for retail

You want a 5-balloon bouquet: one 18" centre, four 10" minis.

Item	Helium	Notes
1 × 18"	0.50 cu ft
4 × 10"	4 × 0.15 = 0.60 cu ft
Total	1.10 cu ft

A standard disposable helium cylinder holds 8.9 cu ft, so you get 8 bouquets per cylinder, minus a little for purging and waste — call it 7. If a cylinder costs US$35, helium is about US$5 per bouquet. Price your bouquet with that number in it, not with a guess.

Example 2 — a shop window display

A 40" number balloon set (two digits) filled with helium.

Item	Helium
2 × 40"	2 × 3.75 = 7.5 cu ft

That is almost a full 8.9 cu ft cylinder for one display. This is why most retail displays use air-filled 40" balloons on a frame instead of helium — the visual is nearly identical and the helium cost drops to zero. Helium is for what needs to float, not for what needs to be big.

Example 3 — freight planning

You are ordering 5,000 pcs of 18" balloons. At 200 pcs per carton, that is 25 cartons.

If the carton measures 55 × 40 × 35 cm, the total volume is 25 × 0.077 m³ = 1.9 m³. A 20ft container holds roughly 28 m³ usable, so this order occupies about 7% of a container — meaning it will almost certainly ship LCL (less than container load), and your per-unit freight cost will be higher than a full-container buyer's.

This is why mixed orders matter. Adding 2,000 pcs of 10" balloons (4 cartons) and 500 pcs of 22" (5 cartons) barely changes your freight but gives you a much broader product range to sell.

Sizes by use case

Use case	Recommended sizes	Why
Retail peg display	18", 10" mini	Standard hook size, good margin per unit
Helium bouquet	18" centre + 10" accents	Best helium-to-impact ratio
Birthday number set	32" or 40"	Readable from across a room
Shop window / photo wall	40", 36"	Maximum visual at minimum unit count
Balloon arch / garland	10", 18" (air-filled)	Fill volume, cheap per metre
Table centrepiece	18" on a weight	Stable, low helium
Gender reveal	36" or 40"	Impact at the reveal moment
Corporate / promo	18", 22" custom printed	Readable logo at arm's length

The sizing mistakes that cost money

1. Ordering by flat size.
An 18" balloon measures 46 cm inflated but roughly 30 cm flat. If you plan a display using flat dimensions, everything will be 50% bigger than you expected and will not fit the frame.

2. Assuming all 18" balloons are the same.
An 18" round, an 18" heart and an 18" star all have different internal volumes. A heart holds roughly 15% less helium than a round of the same nominal size, so it floats for less time. If a customer complains that hearts "sink faster," this is why.

3. Ignoring the carton count when comparing quotes.
Two suppliers quote US$0.52 per 18" balloon. One packs 200 per carton, the other packs 150. On 5,000 pcs that is 25 cartons versus 34 — a 36% difference in freight volume. Always compare landed cost per unit, not FOB price per piece.

4. Using helium for oversized decor.
Every 40" balloon filled with helium costs roughly US$1.50–2.00 in gas alone. A shop window with eight of them burns US$12–16 in helium per reset. Air-filled on a frame costs nothing and lasts longer.

5. Forgetting the weight.
A helium-filled 18" balloon needs roughly 5 g of counterweight; a 22" needs 8 g; a 40" needs 20–25 g. If you sell bouquets without weights, customers tie them to furniture and the balloons rise into the ceiling — a small thing that generates a lot of complaints.

Custom sizes: what is actually possible

Foil balloons are made from a die-cut shape, so "custom size" means "custom die." Practical constraints:

Below 10" — possible but the valve takes up a large share of the surface, and print detail is lost. Not recommended for anything with a logo.
10" to 40" — the standard working range. Most shapes can be scaled within it.
Above 40" — possible up to roughly 60", but film thickness must increase (typically 20μm to 24μm) or the seam fails under helium pressure. Expect a higher unit cost and a longer lead time.
Non-round shapes (animals, characters, objects) need a new die regardless of size, so a custom shape and a custom size carry the same tooling cost — usually a few hundred dollars, one time.

Rule of thumb: if you are changing the size of an existing shape, ask whether the die can be scaled or must be remade. Scaling is cheap; remaking is not.

Frequently asked questions

What is the most popular foil balloon size?
18" is the volume leader for retail and helium bouquets — it is the best balance of visual impact, helium cost and carton efficiency. 40" dominates for photo walls and number sets.

How many 18" balloons fit in a carton?
Typically 200 pcs, though this varies by supplier and by whether the balloons are bulk-packed or individually bagged. Individually bagged 18" balloons usually run 100–150 per carton because the bags add volume.

How much helium does a 40" number balloon need?
About 3.5–4.0 cu ft. Two digits will consume nearly a full standard 8.9 cu ft disposable cylinder.

Do foil balloons come in half sizes?
Rarely. The industry works in whole-inch nominal sizes (10", 18", 22", 24", 28", 36", 40"). Some suppliers offer 20" or 26" for specific shapes, but these are not standard stock.

Why do my 18" balloons float for less time than the spec says?
Three usual causes: under-inflation (a balloon filled to 85% has less lift and less reserve), cold ambient temperature, or a slow valve leak. Check the valve first — it is the most common failure point and the cheapest to fix.

The short version

18" is the workhorse: best impact per cent of helium, best carton efficiency.
40" is for impact, not for floating — use air on a frame unless the float is the point.
Compare landed cost per unit, not FOB price, and always ask how many pieces are in a carton.
Air-filled lasts months; helium-filled lasts days. Decide which you are selling before you design the product.

Wonabo produces foil balloons from 10" mini to 40" jumbo, in round, heart, star, number, letter and custom shapes — 18 production lines, 400,000 pcs per day, factory direct since 2012. Tell us your size mix and we will send a carton-quantity and freight estimate with the quote.

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