Poly bag size finder: what size bag do I need?
Enter your item's size and weight. You get the smallest bag that fits, for flat, reclosable or gusseted bags, and a suggested thickness. Bags are measured width × length, flat, inside the seals.
Thickness guide
| Item | Typical bag thickness |
|---|---|
| Light items under 1 lb: parts, papers, apparel | 1–1.5 mil |
| General items 1–5 lb | 2 mil |
| Heavier items 5–15 lb | 3 mil |
| Over 15 lb, sharp corners, or hardware | 4–6 mil |
1 mil = 25.4 microns = 100 gauge. Convert with the micron to mil converter.
Shop poly bags
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- Poly bag sizes & gauges chart
Questions & answers
How do I measure for a poly bag?
Add the item's thickness to both its width and its length, then allow about 1/2 in. of room. A 10 × 8 × 2 in. item needs a bag about 10.5 × 12.5 in., so an 11 × 13 or 12 × 14 in. bag works.
How are poly bag sizes listed?
Width first, then length, measured flat and inside the seals. The opening is on the width side. Thickness is in mil (thousandths of an inch).
When should I use a gusseted bag?
For thick or boxy items, about 4 in. or more. A gusset is a fold in the sides that opens out, so the bag takes the item's depth without needing a much wider bag.
How much bigger should a reclosable bag be?
Allow about 1 in. more length than a flat bag so the zipper closes without straining over the item.