Ordering too much void fill wastes money. Too little means damaged goods and chargebacks. Getting the number right matters — especially when you're shipping hundreds or thousands of boxes a day.
This guide gives you a simple formula, a ready-to-use reference table, and a worked example so you can calculate your void fill needs accurately before placing your next order.
The amount of void fill you need depends on one thing: how much empty space is inside your shipping box after the product is placed.
We call this the void volume.
Void Volume = Box Volume − Product Volume
Box Volume = Length × Width × Height (of the shipping box)
Product Volume = Length × Width × Height (of the product + inner packaging)
Once you know your void volume, multiply by a fill factor based on your fragility level:
| Fragility Level | Examples | Fill Factor |
|---|---|---|
| Low fragility | Clothing, soft goods, books | 30–40% of void volume |
| Medium fragility | Electronics accessories, cosmetics, small appliances | 50–70% of void volume |
| High fragility | Glassware, ceramics, precision instruments | 80–100% of void volume |
Let's say you're shipping a cosmetics set:
Shipping box: 40cm × 30cm × 25cm = 30,000 cm³
Product (with inner box): 30cm × 20cm × 15cm = 9,000 cm³
Void volume: 30,000 − 9,000 = 21,000 cm³
Fragility level: Medium → fill factor 60%
Void fill needed per box: 21,000 × 60% = 12,600 cm³ ≈ 12.6 litres
If you ship 500 boxes/day, your daily void fill need is:
12.6 litres × 500 = 6,300 litres of void fill per day
Different void fill materials are sold in different units. Use this conversion table:
| Material | Typical Coverage per Unit | Units Needed for 6,300 L/day |
|---|---|---|
| Air cushion film (pillow type, standard roll) | 1 roll ≈ 300–500 litres inflated | ~13–21 rolls/day |
| Air column roll (column type) | 1 roll ≈ 200–400 litres inflated | ~16–32 rolls/day |
| Bubble wrap (standard roll, 50cm wide) | 1 roll (100m) ≈ 250–350 litres | ~18–25 rolls/day |
| Kraft paper / honeycomb paper | 1 roll ≈ 150–250 litres (crumpled) | ~25–42 rolls/day |
Note: Actual coverage varies by inflation level, box shape, and packing method. These figures are conservative estimates for planning purposes.
Once you have your daily usage, calculate your monthly order quantity to avoid stockouts:
Monthly Order Qty = Daily usage × Working days × Safety buffer (1.2)
Example: 21 rolls/day × 22 days × 1.2 = 554 rolls/month
The 1.2 safety buffer accounts for peak shipping days, returns, and damaged rolls. We recommend ordering at least 20% above your base calculation.
Use this table to estimate material needs based on your daily shipment volume (medium fragility, standard box size 40×30×25cm):
| Daily Shipments | Air Cushion Film Rolls/Month | Bubble Wrap Rolls/Month | Honeycomb Paper Rolls/Month |
|---|---|---|---|
| 100 boxes/day | ~110 rolls | ~130 rolls | ~200 rolls |
| 300 boxes/day | ~330 rolls | ~390 rolls | ~600 rolls |
| 500 boxes/day | ~554 rolls | ~660 rolls | ~1,000 rolls |
| 1,000 boxes/day | ~1,100 rolls | ~1,300 rolls | ~2,000 rolls |
For high-volume B2B shippers, air cushion film consistently delivers the lowest cost per litre of void fill:
Storage: Ships uninflated — 1 pallet of film = 8–10 pallets of pre-inflated bubble wrap
Cost per litre inflated: Air cushion film is typically 30–50% cheaper than bubble wrap at equivalent volume
Weight: Uninflated film adds minimal shipping weight to inbound logistics
Customization: OEM printing available on air cushion film rolls (minimum quantities apply)
The only upfront cost is an inflating machine ($200–$800 one-time). At 300+ boxes/day, this pays back within weeks.
Q: How do I measure void volume if my product is an irregular shape?
A: Use the bounding box method — measure the longest, widest, and tallest points of the product and treat it as a rectangle. Then subtract 20–30% to account for the irregular shape leaving less actual void. This gives a conservative (safe) estimate.
Q: Does the fill factor change for air column bags vs air pillow cushions?
A: Yes. Air column bags provide more targeted protection with less total volume — they're placed around the product, not loose-filled. For column-type packaging, use a fill factor 10–20% lower than pillow cushions for the same fragility level.
Q: Can you help us calculate the right quantity for our specific products?
A: Yes. Send us your box dimensions, product dimensions, daily shipment volume, and fragility level — we'll provide a free material recommendation and cost comparison within 24 hours.
Q: What is the MOQ for air cushion film rolls?
A: Standard MOQ starts from 1 carton. For custom sizes or OEM printing, higher MOQs apply. Contact us for details.
Q: Do you supply the inflating machine as well?
A: Yes. We manufacture both air cushion film rolls and compatible inflating machines. Bundled pricing is available for new customers.
Tell us your shipment profile — box size, daily volume, product type — and we'll calculate your monthly material needs and send a competitive quote within 24 hours.
We supply air cushion film, air column rolls, honeycomb paper, and inflating machines from our 6,000㎡ factory in Shanghai. Certifications: GRS, RoHS, ISO9001, CE.
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