Grip Seal Bag Sizes: How to Choose the Right Size
Choosing the right grip seal bag is easy once you know how sizes are measured and what to allow for. This guide explains how to measure your item, how much spare room to leave, and which of our 16 sizes suits what you are packing. Prefer inches? See our size chart in millimetres, centimetres and inches.
Measure the width and height of your item, then choose the smallest bag whose internal size is at least 5mm to 10mm bigger in both directions. If you are packing several items together, measure them as they will sit in the bag.
How are grip seal bag sizes measured?
Sizes are given as internal dimensions: opening width x height. A 100mm x 100mm bag (about 3.9 x 3.9 inches) is 10cm wide at the opening and 10cm tall on the inside, so anything you put in it must fit within those measurements. The first number is always the width of the opening, which is the edge with the grip seal strip.
The grip seal strip sits near the top of the bag, so the space you can actually use for your item is slightly less than the full height. That is why a little spare room matters.
How to measure your item
Step 1: Measure the widest point
Lay the item flat and measure across its widest point. This must be smaller than the first number in the bag size.
Step 2: Measure the length
Measure from end to end. This must be smaller than the second number in the bag size, with a little spare for the seal.
Step 3: Allow for thickness
Bulky or thick items make a bag narrower when it is full, so a flat card and a chunky item of the same width will not need the same bag. If it is thick, go up a size.
Step 4: Add spare room
Allow around 5mm to 10mm extra in each direction so the item slides in easily and the seal closes along its whole length. A tight fit puts pressure on the seal.
Grip seal bag sizes and what they suit
| Size | In centimetres | Typical uses |
|---|---|---|
| 20 x 20mm | 2 x 2cm | Single beads, tiny charms, very small screws |
| 25 x 25mm | 2.5 x 2.5cm | Small beads and findings, tiny fixings |
| 30 x 30mm | 3 x 3cm | Earring backs, small screws, jewellery findings |
| 40 x 40mm | 4 x 4cm | Studs, small clips, memory cards |
| 45 x 45mm | 4.5 x 4.5cm | Small rings, washers, small spare parts |
| 50 x 50mm | 5 x 5cm | Earrings, small parts sets, labels |
| 55 x 65mm | 5.5 x 6.5cm | Small accessories, buttons, small components |
| 60 x 40mm | 6 x 4cm | Narrow items, cable ends, keys |
| 60 x 60mm | 6 x 6cm | Small spare parts, accessories |
| 60 x 90mm | 6 x 9cm | Small tools parts, memory sticks, chains |
| 70 x 105mm | 7 x 10.5cm | Fixing kits, bracelets, small accessories |
| 80 x 120mm | 8 x 12cm | Parts kits, cables, keys, leaflets (small) |
| 100 x 100mm | 10 x 10cm | Fixings kits, small cables, business cards |
| 125 x 125mm | 12.5 x 12.5cm | Chargers, earphones, bundled small items |
| 150 x 150mm | 15 x 15cm | A6 leaflets, larger parts, bundled kits |
| 200 x 100mm | 20 x 10cm | Long, narrow items, pens, cables, tools |
These are suggestions only. Always check against your own item.
Common mistakes when choosing a size
- Choosing by item length only. Check width and thickness too.
- Forgetting the seal. The grip strip uses a little of the bag height.
- Mixing up the numbers. The first number is the opening width.
- Ordering a very tight fit. A slightly larger bag closes more easily and lasts longer.
Choosing the right pack size
Our packs range from 30 to 2,000 bags, depending on the size, and the price per bag falls as the pack gets bigger. If you are trying a size for the first time, start with a pack of 100. Once you know what you use, a larger pack is better value. For regular large volumes see wholesale grip seal bags.
Frequently asked questions
Are grip seal bag sizes internal or external?
Internal. The size is the usable space inside the bag, opening width x height.
What if my item is between two sizes?
Go up to the larger one. A bag that is slightly too big is better than one that is a tight fit.
Can I put more than one item in a bag?
Yes, but measure the items as they will sit together, and allow for the extra thickness.
Do you sell sizes in inches?
Our sizes are listed in millimetres and centimetres. Use the size chart to find the nearest inch size.
Ready to order?
Browse our grip seal bags in 16 sizes, or use the size guide if you are not sure which to choose. Need larger quantities? See our wholesale grip seal bags.