What is a baker's percentage?

Baker's percentages express every ingredient as a percentage of the total flour weight. Flour is always 100%, so a dough with 1,000 g of flour and 720 g of water is 72% water — its hydration. Because the numbers are relative, a formula written this way scales to any batch size.

How to calculate it

Divide each ingredient's weight by the total flour weight and multiply by 100:

ingredient % = ingredient weight ÷ total flour weight × 100

The percentages add up to more than 100% — the total formula percentage. For the example above, with 20 g salt (2%) and 10 g yeast (1%), the total is 175% and the dough weighs 1,750 g.

Scaling a formula to a dough weight

To make a specific amount of dough, divide the target dough weight by the total formula percentage to get the flour weight, then apply each percentage. For 875 g of the dough above: 875 g ÷ 1.75 = 500 g flour, 360 g water, 10 g salt and 5 g yeast.

Using more than one flour

When a dough uses several flours — bread flour with whole wheat, rye or spelt — they are added together to make the 100% base, and each flour is shown as its share of it. A dough with 700 g bread flour, 200 g whole wheat and 100 g rye is 70% / 20% / 10%, and the flours always total 100%.

Hydration with milk, eggs or starter

Hydration is the total water as a percentage of flour. Water counts in full, but milk is about 88% water and a whole egg about 76% (USDA FoodData Central), so 100 g of milk adds about 88 g of water. A sourdough starter kept at 100% hydration is half water and half flour. Recipes usually leave the starter's flour out of the flour base (so starter is, say, 3.2% of the flour), which gives “formula” hydration. “True” hydration also counts the starter's flour — slightly lower — and the calculator shows both.

Why weigh instead of measuring cups?

A cup of flour can weigh anywhere from about 120 g to 160 g depending on how it's filled. Baker's percentages only work with weights, which is why this calculator — like every Weighbench tool — works in grams, kilograms, ounces or pounds, never volume.