The most important thing to know first: the vast majority of advertising inflatables do not need helium at all. If you're ordering a custom inflatable letter, event tunnel, product replica, or mascot character, you will receive it with a blower fan. No helium involved.
Helium is only relevant for one specific product type: inflatables engineered to float freely in the air, tethered by lines. These are called cold-air parade balloons or tethered advertising balloons. Everything else — and this covers 95% of advertising inflatable products — uses air from a blower or pump.
Which Inflatables Need Helium vs Air
Uses Helium
- →Tethered floating advertising balloons
- →Parade balloon floats (helium type)
- →Floating promotional blimps
- →Sky balloons at fixed altitude
Uses Air (Blower or Pump)
- →Inflatable letters & logo signs
- →Giant product replica bottles/cans
- →Event tunnels & arches
- →Mascot & character inflatables
- →Inflatable animals & plants
- →Christmas Santa & seasonal displays
- →Giant DJ stages & event structures
- →Sealed decorative balloon displays
How to Calculate Helium Volume
For spherical floating balloons, the volume formula is straightforward. For custom shapes, use an approximate equivalent sphere diameter.
// Sphere volume formula
V = (4/3) × π × r³
where r = radius (diameter ÷ 2), result in cubic metres
// Required helium
Helium (litres) = V (m³) × 1000 × 1.15
+15% safety margin for leakage and temperature
| Diameter | Volume | Helium Required | Float Result |
|---|---|---|---|
| 0.5m | 0.065 m³ | ~70 litres | No — too small to lift its own weight |
| 1.0m | 0.52 m³ | ~550 litres | Marginally — depends on material weight |
| 1.5m | 1.77 m³ | ~1,900 litres | Yes — with tether required |
| 1.8m | 3.05 m³ | ~2,800 litres | Yes — tether required |
| 2.0m | 4.19 m³ | ~4,000 litres | Yes — strong tether required |
| 2.5m | 8.18 m³ | ~7,500 litres | Yes — professional rigging advised |
| 3.0m | 14.1 m³ | ~13,000 litres | Yes — professional rigging required |
Helium vs Blower: Cost Comparison
For ground-based advertising displays, using a blower instead of helium is dramatically more cost-effective and operationally simpler.
Helium (1.8m floating balloon)
- →Helium cost: $80–$200 per fill (market rate varies)
- →Refill every 24–72 hours during event
- →Professional rigging required at height
- →Weather-sensitive — wind causes handling issues
- →Cannot be used indoors without ventilation
- →Float duration limited
Blower (ground advertising inflatable)
- →Blower included with product (no recurring cost)
- →Runs continuously on standard power (150–400W)
- →Setup in 3–15 minutes by 1–2 people
- →Stable in winds up to 40 km/h with anchoring
- →Suitable for indoor and outdoor use
- →Indefinite display duration while powered
Frequently Asked Questions
Do advertising inflatables need helium?
No. The vast majority of advertising inflatables — including giant letters, product replicas, event tunnels, mascot characters, and most balloon-style displays — use a continuous-airflow blower fan, not helium. Helium is only needed for inflatables designed to float freely in the air, such as cold-air parade balloons and tethered floating balloon signs.
How much helium do I need for a 1.8 metre inflatable balloon?
A spherical 1.8-metre diameter balloon has a volume of approximately 3.05 cubic metres (3,050 litres). However, helium expands after filling, and not all that volume needs to be pure helium — a mixture is common. In practice, a 1.8m sphere typically requires 2.5–3.0 cubic metres (2,500–3,000 litres) of helium to achieve full float with a safety margin. Always add 10–15% above the calculated volume to account for minor leakage and temperature changes.
Why do different suppliers give such different helium estimates?
Helium volume estimates vary because they depend on balloon shape (sphere vs custom shape), material porosity (PVC vs nylon — nylon loses helium faster), desired float duration, ambient temperature, and altitude. A supplier quoting 28 litres for a 1.8m balloon and another quoting 4,000 litres are likely describing different product types or making calculation errors. Always ask for the calculation methodology and the product's volume specification.
Can I use air instead of helium to inflate an advertising inflatable?
Yes — for ground-based advertising inflatables. Air (from a blower or electric pump) is the correct inflation method for all ground-mounted advertising inflatables. These products are not designed to float and do not need helium. Only inflatables specifically engineered to float — with sealed seams, appropriate material porosity, and lift-to-weight ratios calculated for helium — require helium.
How long does helium last in an inflatable balloon?
In a PVC inflatable balloon, helium typically lasts 24–72 hours before the balloon needs a top-up. Nylon and foil materials lose helium faster (12–24 hours). Temperature drops at night cause air contraction and apparent deflation; re-inflation in the morning restores shape. For events longer than one day, plan for helium top-ups and have a small reserve cylinder on hand.
Not Sure Which Product Type You Need?
Tell us your event type, venue, and what you're trying to display — we'll recommend the right product and inflation method in one message, free of charge.
View Full FAQ