Loose fill is the cheapest void filler per cubic foot and the easiest to misuse, because it settles in transit and lets contents drift toward a wall. UPS answers that in its own guidance by asking for a minimum of two inches of cushioning around the contents, and by telling shippers to keep flat or narrow products out of peanuts entirely.
The calculator sizes the packed carton, then prices it across carriers in one pass.
Bags marked loose fill hold one of three materials, and the difference shows up in damage claims and in what your recipient has to do with the mess.
None of the three is a cushion in the engineering sense. Loose fill stops movement; it does not absorb a drop the way a wrapped layer against the product does. That distinction is why carrier guidance always pairs fill with a wrap, and why the fragile method starts at the product surface rather than at the box.
Read those together and the failure mode is obvious. A box of loose fill vibrates for two days on a belt, the fill compacts, and anything flat migrates until it is resting against corrugated with nothing between it and the outside world. UPS offers a fix in the same document: flat pieces of corrugated fiberboard may also be used between contents and peanuts to help prevent migration. A stiff pad on each face costs almost nothing and stops the drift that the fill alone cannot.
The other half of the fix is filling to the brim and closing under slight pressure, so the flaps push down on the load. If you can shake the sealed box and hear anything move, the fill has already lost. Our void fill comparison covers the shake test and the materials that do not settle.
Peanuts win on price per cubic foot by a factor of two over inflatables, which is the whole reason they survive in an era of better materials.
| Material and item | Listed price | Coverage as listed | Cost per unit |
|---|---|---|---|
| Biodegradable peanuts, Uline S-1564 | $24 | 12 cubic feet per bag | $2.00 per cu ft |
| Inflatable pillows, Uline S-13698 | $101 per carton | 250 bags at 0.1 cu ft each | $4.04 per cu ft |
| Kraft paper roll, Uline S-3574 | $32 | 18 in x 1,200 ft | $0.027 per ft |
| Bubble roll, Uline S-3927P | $49 | 12 in x 750 ft | $0.065 per ft |
The paper and bubble rows are priced per linear foot rather than per cubic foot because they are wraps, not pours, and comparing them by volume would flatter one side. What the table does show is that no void filler is expensive relative to a label. Getting a cubic foot of protection costs single-digit dollars; getting the box size wrong costs multiples of that, which the next table makes plain.
Here is the trap. Reaching for a roomier carton so there is space for a generous pour is the single most expensive packing habit there is, because carriers bill the air.
| Carrier | Service | Price | Transit window returned |
|---|---|---|---|
| UPS | Ground Saver | $20.50 | Not returned for this row |
| FedEx | Ground Economy | $20.51 | 6-7 business days |
| USPS | Ground Advantage | $23.69 | 8-9 business days |
| UPS | Ground | $23.70 | 2-3 business days |
| FedEx | Ground | $32.23 | 5-6 business days |
The identical 5 lb in a 12 by 10 by 6 carton quoted $13.52 on the same lane the same day. Going up to 18 by 14 by 10 to make room for fill added $6.98 to the cheapest row, which at the listed price buys about three and a half cubic feet of loose fill. Fill the gaps you need, not the gaps you created; the dimensional weight walkthrough shows the arithmetic that turns those inches into billable pounds.
At least two around the contents on every side. The UPS packaging guidelines state that due to the shifting and settling properties of peanuts, you should use a minimum of two inches of cushioning around the contents of the box, read on ups.com 2026-07-28.
Loose fill is a pile of separate pieces, and days of vibration compact that pile. UPS warns against using peanuts with flat or narrow products that may move to the edge or bottom of the box in transit, and suggests flat pieces of corrugated fiberboard between the contents and the fill to prevent migration.
About two dollars. Uline listed a 12 cubic foot bag of biodegradable peanuts at $24 on 2026-07-28, which works out to $2.00 per cubic foot. Inflatable pillows on the same site worked out to $4.04 per cubic foot at the listed carton price and bag volume.
Only the anti-static kind, and not on their own. UPS states that peanuts cause static electricity and may damage electronic items, and asks for anti-static peanuts for electronic items along with bubble sheeting around the item itself.