A garbage bag that is too narrow won't go around the rim, and one that is too short slips into the bin when it fills. Two measurements of the bin, plus the overhang you want, are enough to work out the right size.
How to measure your bin
- Rim: measure across the top opening. For a round bin, that is the diameter; for a square or rectangular bin, measure both sides.
- Height: measure from the rim to the bottom, inside the bin.
- Overhang: decide how much bag should fold over the rim to hold it in place.
Garbage bag size formulas
| Bin shape | Flat width | Length |
|---|---|---|
| Round | π × diameter ÷ 2 | height + diameter ÷ 2 + overhang |
| Square or rectangular | length + width of the rim | height + shorter side ÷ 2 + overhang |
Why these work: an opened bag is a tube twice its flat width around, so its flat width must be half the rim's perimeter. The bottom seal has to reach the middle of the base, which uses up half the bin's width in extra length.
Worked examples
- Round bin, 40 cm across and 60 cm tall, 10 cm overhang: about 63 × 90 cm.
- Rectangular bin, 40 × 30 cm rim and 60 cm tall, 10 cm overhang: 70 × 85 cm.
Choosing garbage bag thickness
The right thickness depends on the weight of the waste, whether it has sharp edges, and how the bag is handled and lifted. As a guide:
- Light, dry everyday waste (offices, paper, packaging): thinner film is usually enough. HDPE is common here because it is strong and light for its thickness.
- Heavy, wet or bulky waste (kitchens, facilities): choose thicker film or a softer LDPE/LLDPE blend that stretches instead of splitting.
- Sharp or industrial waste (offcuts, broken materials): choose a heavy-duty bag, with thicker film and more LLDPE for puncture resistance.
Thickness is usually quoted in micron. If a supplier quotes gauge or mil, convert it with our thickness converter, which also estimates how many bags you get per kilogram. For how the materials differ, see LDPE vs HDPE vs LLDPE.
Colors for waste separation
Different bag colors are commonly used to keep waste streams apart, such as general waste and recyclables, so bags can be sorted at a glance. Tell us which colors your site uses when you order.
What to send for a garbage bag quote
- Your bin size, or the bag width and length you need
- Thickness in micron, or what the bags will hold
- Color
- Flat-packed or on a roll
- Quantity
Send these through our quote form, or see our garbage bags page.
