Baker’s Percentage Calculator
Grams of water, salt and starter for any flour or dough weight, at the hydration you want.
Good to know. In a baker’s recipe the flour is always 100%, so the percentages add up to more than 100. That is the point.
How it works
In plain words
Each ingredient is a percentage of the flour. Multiply the flour by each percentage for its weight. Starting from the dough, divide the dough weight by the sum of all the percentages (with flour as 100%) to find the flour.
The formula
ingredient = flour × percentage flour = dough ÷ (100% + water% + salt% + starter%) true hydration = (water + starter ÷ 2) ÷ (flour + starter ÷ 2)
Worked example
500 g of flour at 70% hydration takes 350 g of water, with 10 g of salt (2%) and 100 g of starter (20%): 960 g of dough. Counting the starter’s own flour and water, the hydration is 72.7%.
Sources
No outside data or rates: this is plain arithmetic.
3 automated tests check its answers on every change.
About the baker’s percentage calculator
Bakers write recipes as percentages of the flour, which always counts as 100%. A dough at 70% hydration has 70 g of water for every 100 g of flour, whatever the batch. That makes it easy to scale a recipe up or down, compare two recipes, or change one thing at a time.
Hydration shapes the bread. Around 60–65% gives a firm dough for sandwich loaves and bagels; 70–75% is typical of a rustic or sourdough loaf; 80% and above makes the open, holey crumb of a ciabatta, and a wet dough that is harder to handle. Wholemeal and rye flours soak up more water than white flour, so they need more for the same feel. Salt is nearly always about 2%.
A sourdough starter fed with equal weights of flour and water is itself half flour and half water, so it adds to both. The last result counts that in: the “true” hydration is a little higher than the recipe’s figure when a lot of starter is used.
Start from the dough to plan a bake: two loaves of 900 g or six pizzas of 250 g, and the calculator works out the flour. For pizza size, use the pizza calculator; to scale any recipe, the recipe scaler.
Questions people ask
What is baker’s percentage?
Each ingredient as a percentage of the flour, which counts as 100%. 70% water means 700 g of water for 1 kg of flour.
How much water for 500 g of flour?
It depends on the hydration: 325 g at 65%, 350 g at 70%, 375 g at 75%.
How do I work out flour from the dough weight?
Divide the dough weight by the sum of the percentages. 1,800 g of dough at 70%, 2% and 20% is 1,800 ÷ 1.92 ≈ 938 g of flour.