Incorrect bag measurements are one of the fastest ways to receive a wrong quote. For B2B ordering, the supplier needs the finished bag dimensions, the construction details and the thickness basis before material use, packing volume and production feasibility can be reviewed.
How do I measure bag width and height?
Measure the flat finished bag from side to side for width, then from opening or closure reference point to bottom seal for height. If the bag has a zipper, adhesive flap or header, write whether that feature is included in the height or listed separately.
Basic flat bag measurement
- Width: left edge to right edge on the finished flat bag.
- Height: opening to bottom seal, or the buyer-defined usable height.
- Tolerance: state the acceptable plus/minus range if the product fit is tight.
How do I measure gusseted poly bags?
For gusset bags, list the flat width, height and gusset depth separately. A gusset is not just extra width; it changes capacity, film consumption, carton volume and sometimes the sealing method.
Common gusset details to confirm
- Side gusset or bottom gusset.
- Gusset depth after folding.
- Whether the product needs to stand, hang or lie flat after packing.
How do zipper, flap, header and hang holes affect measurement?
Closure and display features must be separated from the usable product space. A zipper, adhesive flap, header card zone or hang hole area can reduce the usable height even when the total outer height looks correct.
| Feature | What to Measure | Why It Matters |
|---|---|---|
| Zipper | Inside usable space below the zipper and total outer height | Prevents the product from blocking the closure |
| Adhesive flap | Flap length, tape position and finished height | Controls sealing overlap and display fit |
| Header or hang hole | Header area, hole position and usable product area | Keeps retail display holes away from the product |
| Gusset | Flat width, height and gusset depth | Changes bag capacity and material consumption |
How should thickness be written in a custom poly bag RFQ?
Thickness must state the unit and measurement basis. Buyers often use micron, millimetre or mil, but the key is whether the value means one wall, two walls together or a measured finished-bag average.
Thickness checklist
- Write the unit, such as 50 micron, 0.05 mm or 2 mil.
- State whether it is per wall or total thickness.
- Provide an acceptable tolerance if the buyer has a receiving inspection standard.
What should I send before requesting a quote?
A complete RFQ reduces back-and-forth and makes quotes easier to compare. Send product photos, current bag sample photos, finished dimensions, material preference, thickness, quantity, artwork, packing method, destination and requested Incoterm.
If you need a quick specification review, start from custom PE bags, flat bags or film rolls and attach your product measurements.
FAQ
Should I measure the product or the bag?
Measure both. The product dimensions show the required fit, while the finished bag dimensions define the quotation and production specification.
Does gusset depth count as part of width?
List gusset depth separately unless your drawing clearly defines the total open width. This avoids confusion between flat width, expanded capacity and material consumption.
Can a supplier quote if I only have product photos?
Photos help feasibility review, but they are not enough for a final quote. The supplier still needs finished dimensions, thickness basis, material, quantity, packing and destination details.
Want us to check your measurements?
Send a drawing, product size or current bag sample photo for a custom poly bag specification review.
Request Measurement Review