If you’re asking yourself: What size bin bags do you need for a 30 litre bin? A 30-litre bin usually needs a liner labelled for a 30-litre bin, but the litre rating alone doesn’t guarantee a good fit. Check the bin’s opening width, shape and height, then compare those measurements with the flat width and length of the bin bag. A bag that’s labelled 30L can still be too narrow for a wide, shallow bin or too short to fold over a tall one.
For a branded bin, the quickest answer may be the manufacturer’s liner code. For example, many Brabantia bins in the 23–30L range use PerfectFit Code G, but not every Brabantia 30L bin does: certain Bo and FlatBack+ configurations use Code O. Check the code printed inside your particular bin before ordering.
How to measure for a 30-litre bin bag
You need a tape measure and three measurements:
- Opening: For a round bin, measure the diameter across the top. For a rectangular bin, measure its inside width and inside depth.
- Height: Measure from the inside bottom to the rim.
- Overhang: Decide how much extra bag you want to fold over the rim, often around 10–15cm.
Bin-bag dimensions are usually quoted as flat width × length, rather than the width of the bag when it is opened.
Estimate the flat bag width
| Bin opening | Approximate minimum flat bag width |
|---|---|
| Round | Opening diameter × 1.57 |
| Rectangular | Inside width + inside depth |
For example, a round opening 30cm across needs around 47cm of flat bag width to reach around the rim (30 × 1.57 ≈ 47). Allow a little extra for comfortable fitting and manufacturing differences.
A rectangular opening measuring 25cm × 20cm needs around 45cm flat width (25 + 20 = 45), ideally with some allowance.
These are geometry-based starting points, not guarantees: drawstrings, seams, gussets, stiff rims and the way a liner is folded can affect the actual fit.
Estimate the bag length
Start with the bin’s internal height, then add some material to cover the bottom and fold over the top.
- Round bin: internal height + half the opening diameter + desired overhang.
- Rectangular bin: internal height + approximately half the base diagonal + desired overhang.
Worked example: A round bin measuring 45cm high with a 30cm opening and a 10cm overhang calls for roughly 70cm of bag length (45 + 15 + 10). Combine that with the approximate 47cm minimum flat width and look for the next comfortably larger liner dimensions.
These measurements are illustrative: don’t assume all 30L bins have those proportions.
Is a 30-litre bin bag always the right choice?
Not necessarily. Two bins can hold 30 litres but be completely different shapes. A tall, narrow bin needs a longer liner; a short, wide bin may need a wider one. This is why matching centimetre measurements is more dependable than matching litres alone.
If your liner keeps slipping into the bin, it might not have enough width or overhang. If it bunches excessively at the bottom, it may be unnecessarily long. A slightly generous fit is generally easier to live with than a liner stretched tightly around the rim.
What size bags fit a Brabantia 30L bin?
Don’t assume all Brabantia 30-litre bins use the same bag. Brabantia lists Code G for many 23–30L bins, while its range also includes Code O for certain 30L Bo/FlatBack+ bins. Look for the letter or colour code inside the lid or body, or check the model’s manual.
If the label says G, buy Code G liners. If it says O, buy Code O. The exact code matters more than choosing an unrelated bag simply labelled 30L.
What to look for when buying replacement liners
Before buying a multipack, check:
- Flat dimensions: The listed width and length meet the measurements you took.
- Bin model or liner code: Especially important for fitted branded bins.
- Closure: Drawstring or tie handles can make removal easier, but don’t substitute for the right size.
- Strength: Food waste or heavier rubbish may call for sturdier material than lightweight bathroom waste.
- Pack size: Try a small pack before ordering 100 or more bags if you’re unsure of fit.
Shopping shortcut: See 30-litre bin liners on Amazon UK. For Brabantia, check the code first: Code G liners or Code O liners.
Frequently asked questions
Can I use a 40-litre bag in a 30-litre bin?
Often yes, provided the bag is wide enough to clear the rim. It may leave extra material at the bottom or around the edge. Check its actual dimensions, not just the 40L label.
Why won’t my 30-litre bin bags fit my 30-litre bin?
The stated capacity measures volume, not shape. Your bin might be wider, taller or more rectangular than the bags were designed for. Measure the bin opening and compare it with the bag’s flat width and length.
Should a bin liner hang over the rim?
A small fold-over allowance helps keep the liner in place and makes it easier to remove without touching the bin interior. Around 10–15cm is a practical starting point, though some fitted liners are designed to sit almost invisibly under the lid.
Do all 30-litre Brabantia bins use Code G?
No. Code G fits many Brabantia bins in the 23–30L range, but some 30L models call for a different code, including Code O. Check the bin’s own code label.
Bottom line about What size bin bags do you need for a 30 litre bin
For a 30-litre kitchen bin, start with a 30L liner but choose by measurements or your bin’s official liner code. Measuring the opening and height takes a minute and can save you buying a whole roll of bags that slip, tear or won’t stretch over the rim.