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. The calculator does the same for the baker's percentages, but its hydration counts both the starter's water and its flour: all the water in the dough over all the flour.
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.
Sources: Associazione Verace Pizza Napoletana (AVPN), International Regulations (Disciplinare), 2024; King Arthur Baking, French Bread with Poolish (professional formula); King Arthur Baking, Sourdough Baguettes (professional formula); King Arthur Baking, Brioche (professional formula); King Arthur Baking, Big and Bubbly Focaccia; USDA FoodData Central, Milk, whole, 3.25% milkfat (FDC 171265); USDA FoodData Central, Egg, whole, raw, fresh (FDC 171287); USDA FoodData Central, Butter, without salt (FDC 173430). All sources and how we use them.