Bake Loss Calculator
Bread weighs less than the dough it came from: water evaporates in the oven and keeps leaving while the loaf cools. Use this to scale dough for a loaf that has to weigh a set amount, or to measure what your own bread loses.
Dough weight = baked weight ÷ (1 − loss). An 800 g loaf at 14% loss needs 800 ÷ 0.86 = 930 g of dough.
Typical bake loss by bread type
| Bread | Scaled dough | Cooled loaf | Loss |
|---|---|---|---|
| White tin loaf | 950 g | 820 g | 14% |
| Whole wheat tin loaf | 970 g | 820 g | 15% |
| Small white tin loaf | 485 g | 420 g | 13% |
| Baguette | 550 g | 420 g | 24% |
| Sourdough | 700 g | 530 g | 24% |
Scaling weights from Busby's Bakery's bread-weight table. Long, thin and crusty breads lose the most because more of their surface is exposed; whole grain doughs lose 2–3 points more than white.
Where these numbers come from
- Busby's Bakery — How much weight does bread lose when baked? — overall 10–25%, 15–20% for home and small bakeries, 2–4% of it in the oven itself, table above
- The Fresh Loaf — pre-bake weight to final weight — bakers quoting Jeffrey Hamelman's Bread: roughly 10–20% of dough weight
How it works
Bake loss is the weight a dough loses as water evaporates in the oven and while the loaf cools: (dough weight − cooled loaf weight) ÷ dough weight. To hit a set loaf weight, the calculator divides the target by (1 − loss): 800 g at 14% needs 800 ÷ 0.86 = 930 g of dough.
Dividing by (1 − loss) is not the same as adding the loss percentage on top. 800 g + 14% is 912 g, which bakes out at about 784 g, short of the target. That difference matters when bread is sold by declared weight.
Worked example
You sell 800 g sandwich loaves and your loaves lose about 14%.
Dough per loaf = 800 ÷ (1 − 0.14) = 930 g. For 12 loaves, mix about 11.2 kg of dough.
To check your own figure: a 950 g piece of dough that cools to 820 g lost 130 g, which is 13.7%.
Common mistakes
- Weighing the loaf hot. Loaves keep losing water as they cool, so weigh them fully cool, the way a customer would get them.
- Using one loss figure for every product. A baguette and a tin loaf from the same dough lose very different amounts.
- Forgetting that steam, a darker bake or a longer bake all raise the loss.
- Measuring once. Weigh several loaves over a few bakes and use the average.
When not to rely on it
The preset losses are published rules of thumb. If you sell bread by declared weight, measure your own loss for each product and add a margin; the presets are a starting point only.
Frequently asked questions
How much weight does bread lose when baked?
Usually 10–20% of the dough weight, and up to about 25% for baguettes and long-baked crusty loaves. Only a few percent leaves in the oven itself; the rest goes during baking, cooling and the first hours after.
How do I calculate bake loss?
Weigh the shaped dough, bake, let the loaf cool completely and weigh it again. Bake loss = (dough − loaf) ÷ dough × 100.
How much dough do I need for an 800 g loaf?
Divide by one minus the loss. At 14% loss: 800 ÷ 0.86 = 930 g. At 20%: 800 ÷ 0.80 = 1,000 g.
Why do my loaves lose more than the table says?
Higher hydration, a smaller or longer loaf, a darker or longer bake and cooling in a dry, drafty room all raise the loss. Whole grain doughs lose a little more than white.
Why not just add the loss percentage to the loaf weight?
Because the loss is a share of the dough, not of the loaf. 800 g + 14% = 912 g of dough, which loses 128 g and ends at about 784 g. Dividing by 0.86 gives the correct 930 g.
Read the guide
Last reviewed: 2026-10-25. Found an error? Email contact@bakerymath.com.
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