Void Fill Calculator
Find out exactly how much void fill you need to protect a shipment — and what it costs. Enter your box and product, and get the empty space to fill plus how many air pillows, how much paper or peanuts, and the cost per box and per order.
Recent calculations
- Your recent void fill calculations appear here on this device.
3D void preview
Drag to rotate · the gap is the void fill
- Box volume —
- Product volume —
- Empty (void) space —
Estimates for planning. Material counts depend on pillow size, paper crumple, and how tightly you pack — the goal is no movement without overfilling. Void fill protects the product but does not lower dimensional weight; right-sizing the box does.
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How much void fill do I need?
Void fill is the material that fills the empty space around your product so it can’t shift, rattle, or get damaged in transit. To find how much you need, subtract the product volume from the box interior volume — that empty space is the void to fill. This void fill calculator does the math and converts it into real amounts: how many air pillows, how much paper or packing peanuts, and the cost per box and per order. The goal is simple: fill the gap so nothing moves, without overfilling.
How to calculate void fill
- Box volume. Multiply the box interior length × width × height.
- Product volume. Multiply the product L × W × H, times how many go in the box.
- Find the void. Box volume minus product volume is the empty space to fill.
- Set the fill level. Aim for ~90–100% so the item can’t move — without bulging the box.
- Convert to material. Divide by pillow volume for air pillows; for loose fill, the void volume is the amount of paper or peanuts.
Void fill = (box volume − product volume) × fill %Void fill materials compared
| Material | Best for | Pros | Cons |
|---|---|---|---|
| Air pillows | Most e-commerce; light to moderate items | Light, cheap per box, store flat, ~99% air | Plastic; need an inflator for volume |
| Crumpled paper | Light items & premium unboxing | Recyclable, renewable, brandable | Heavier, more storage, less cushioning |
| Packing peanuts | Irregular shapes | Conform to any shape | Bulky to store, messy, hard to recycle |
| Bubble wrap | Wrapping fragile surfaces | Great surface & shock protection | Wraps rather than fills space; plastic |
Void fill vs. cushioning
Quick test: the product should not move when you gently shake the sealed box — but the box shouldn’t bulge or strain at the seams.
Void fill example
You ship a 9 × 6 × 2 in product in a 12 × 10 × 6 in box. The box holds 720 in³ and the product is 108 in³, leaving 612 in³ (about 0.35 ft³, or 85% of the box) to fill.
That’s roughly 5 medium (8×8) air pillows, or about 0.35 ft³ of paper or peanuts. The smarter long-term fix is a snugger box — less void means less material and lower dimensional weight.
Cut void fill cost the right way
The cheapest void fill is the void you never create. Right-size the box first so there’s less empty space, then add only what you need. Buy void fill on a per-box basis (this tool gives you that number), choose recycled-content or paper options to hit sustainability goals, and remember: void fill protects the product but does not reduce dimensional weight — only a smaller box does that.