Bread bag listings give you a width and a height, which tells you almost nothing, because a loaf is three-dimensional and a flat bag is two.
Here's how to work it out properly, and it takes about a minute.
Measure the loaf, not the bag
Take the loaf you actually buy most weeks and measure two things:
- Its longest dimension — end to end.
- Its girth — a tape measure right round the fattest part, or across the top and down both sides.
Then: the bag's height needs to beat the loaf's longest dimension by about 5 cm, so there's something to roll, fold or zip. The bag's width × 2 needs to beat the loaf's girth, because a flat bag has to open out around it.
That second one is where most people get caught. A 30 cm wide flat bag gives you roughly 60 cm of circumference, minus what the corners eat. A big round boule can want more than you'd guess.
Typical loaves, typical numbers
| Loaf | Roughly | Wants a bag about |
|---|---|---|
| Round boule, 800–900 g | 20–23 cm across, 10 cm tall | 30 cm wide, 33 cm tall |
| Tin loaf / sandwich loaf | 23–28 cm long | 25 cm wide, 33 cm tall |
| Bakery batard | 28–35 cm long | 28 cm wide, 40 cm tall |
| Sliced loaf in its wrapper | 25 cm long | 28 cm wide, 30 cm tall |
| 6 rolls or a stack of buns | — | 25 cm wide, 30 cm tall |
| Full baguette, 65 cm | 65 cm long | see below |
The baguette answer
No. Not ours, not anyone's.
A French baguette runs about 65 cm. A bread bag that took one would be a metre of cloth you couldn't store anywhere, and nothing sold as a bread bag is built that way. Any listing implying otherwise is describing a shorter loaf than the one you bought.
Cut it across the middle and both halves fit comfortably in anything on this page. That's what everyone does, including us.
Our sizes, and which loaf each suits
Where we don't have a confirmed figure from the maker, we've left it out rather than estimate. A guessed dimension is worse than none.
- 42.5 × 31.5 cm — the original bread bag and the Washday. Pick either if you buy big round loaves or aren't sure.
- 43 × 33 cm — the Orchard Leaf, the Bakery Doodle and the Fresh Daily. The widest cut, which takes a round loaf without any persuasion.
- 32 × 43 cm — the Baker's Script. Tall and narrow, so it suits a tin loaf or a stack of rolls rather than a broad boule.
- 30.5 × 43.2 cm — the Honeycomb, whose zip runs across the mouth so the opening lies flat and a wide loaf goes in without being posted through a gap.
When in doubt, go bigger
A loaf with room around it is fine. A loaf being forced into a bag is not — you crush the crust getting it in, and the closure can't do its job because the cloth is already under tension.
The one real cost of a larger bag is a bigger air space, which matters less than people think as long as the loaf went in cool.
The three widest, if you buy round loaves
Sizing is only half of choosing. The other half is how closed you want it — the three levels of closed, and which loaf each suits.