The baker's percentage formula
Baker's % = ingredient weight ÷ total flour weight
Three rules follow from it. All flours together are 100%: a recipe with 900 g bread flour and 100 g whole wheat flour is 90% + 10%. Every other ingredient is a percentage of that flour, not of the dough. And the total of all percentages is always more than 100%, because water, salt and yeast are added on top of the flour. Use the same unit for everything, ideally grams, since cups and spoons of flour vary too much in weight.
Step 1: from a recipe in grams to baker's percentages
The example loaf uses 900 g bread flour, 100 g whole wheat flour, 700 g water, 20 g salt and 6 g instant yeast. The total flour is 1,000 g, so the formula reads 90 / 10 / 70 / 2 / 0.6. In Excel one formula fills the column:
=B2/SUM($B$2:$B$3)
The dollar signs keep the flour range fixed while you copy the formula down. The total of the column, 172.6%, is the number you need for scaling.
Step 2: scale the formula to a target dough weight
Suppose tomorrow's order is 40 loaves with 750 g of dough each: 30,000 g of dough. Since the dough is 172.6% of the flour, work backwards:
Flour = target dough weight ÷ total baker's % = 30,000 ÷ 172.6% = 17,381 g
Every ingredient is then flour × its percentage: 15,643 g bread flour, 1,738 g whole wheat flour, 12,167 g water, 348 g salt and 104 g yeast. The scaled weights add up to exactly 30,000 g, which is the check that nothing was missed. The same two steps scale the recipe to 4 loaves or 400.
Worked example: a loaf formula scaled to 40 × 750 g
The recipe grams and the order are yellow. Column C turns grams into baker's percentages, B12 finds the flour for the order, and column D scales every ingredient from it.
| A | B | C | D | E | |
|---|---|---|---|---|---|
| 1 | Ingredient | Recipe (g) | Baker's % | Scaled (g) | Share of dough |
| 2 | Bread flour | 900 | 90.0% | 15,643 | 52.1% |
| 3 | Whole wheat flour | 100 | 10.0% | 1,738 | 5.8% |
| 4 | Water | 700 | 70.0% | 12,167 | 40.6% |
| 5 | Salt | 20 | 2.0% | 348 | 1.2% |
| 6 | Instant yeast | 6 | 0.6% | 104 | 0.3% |
| 7 | Total | 1,726 | 172.6% | 30,000 | 100.0% |
| 8 | |||||
| 9 | Loaves to bake | 40 | |||
| 10 | Dough per loaf (g) | 750 | |||
| 11 | Target dough weight (g) | 30,000 | |||
| 12 | Flour weight = 100% (g) | 17,381 | |||
| 13 | Hydration (water ÷ flour) | 70.0% |
- C2
=B2/SUM($B$2:$B$3)Baker's % of bread flour - C7
=SUM(C2:C6)Total baker's % - B12
=B11/C7Flour for the order - D2
=$B$12*C2Scaled weight - E5
=C5/$C$7Salt as a share of the dough
Illustrative formula. Real recipes and bake losses vary with the flour, the oven and the product.
Baker's percentage is not the share of the dough
Salt at 2% sounds like 2% of the bread, but it is 2% of the flour. Its share of the whole dough is 2% ÷ 172.6% = 1.2%. Water at 70% of the flour is 40.6% of the dough. The share of the dough is what you need when a regulation or a nutrition label asks about salt in the product, and baker's percentages are what you need to compare and scale formulas.
Hydration, preferments and other liquids
Hydration is water ÷ flour, the water's baker's percentage. Tin loaves are often around 60 to 65%, many crusty hearth breads 68 to 78%, and very open doughs higher. Two adjustments keep the number honest:
- Preferments: the flour and water in a poolish, sponge or sourdough starter count towards the totals. A 100% hydration starter with 200 g in the recipe adds 100 g flour and 100 g water.
- Other liquids: milk is roughly 87% water and whole eggs roughly 75%, so they add to the true hydration even though the formula lists them separately.
Scale for losses before you cost the batch
A bakery does not sell dough. Some dough sticks to the mixer and the bench, and bread loses weight in the oven, roughly 10 to 15% for many lean loaves. If the label promises a baked weight, divide by (1 − bake loss) first to find the dough to scale, then run the baker's percentage steps. Once the weights are right, the cost per loaf follows from the purchase prices, and the selling price from a target margin, see food cost percentage and markup vs margin.
Common mistakes
- Dividing by the total dough instead of the flour. That gives the share of the dough. Baker's percentages always divide by the flour.
- Using only one of several flours as 100%. Whole wheat, rye and bread flour together make 100%.
- Multiplying the target dough weight by each percentage. The percentages apply to the flour. Find the flour first: dough ÷ total baker's %.
- Forgetting the flour and water in the starter. A preferment changes the true hydration and the salt percentage if you leave it out.
- Scaling to the baked weight. Dough loses weight in the oven. Scale to the dough weight you need after allowing for bake loss.
- Measuring by volume. A cup of flour can weigh noticeably more or less depending on how it is filled. Weigh everything in grams.
Frequently asked questions
How do you calculate baker's percentage?
Divide each ingredient's weight by the total flour weight and multiply by 100. With 1,000 g of flour, 700 g of water is 70%, 20 g of salt is 2% and 6 g of yeast is 0.6%.
Why do baker's percentages add up to more than 100%?
Because the flour alone is 100% and every other ingredient is added on top. A simple bread formula usually totals somewhere between about 160% and 185%, the example here 172.6%.
How do I convert baker's percentages to grams?
Decide the dough weight you need, divide it by the total baker's percentage to get the flour, then multiply the flour by each ingredient's percentage. 30,000 g of dough at 172.6% needs 17,381 g of flour and 12,167 g of water at 70%.
What does 70% hydration mean?
The water weighs 70% of the flour: 700 g of water for every 1,000 g of flour. It is the water's baker's percentage, and it should include the water in any starter or preferment.