Sourdough Calculator
Turn a flour weight and your baker’s percentages into water, salt and starter — a full sourdough recipe with total dough weight.
How it works
water = flour × hydration% · salt = flour × salt% · starter = flour × starter% · total dough = flour + water + salt + starter
Sourdough is built on baker’s percentages: every ingredient is stated as a percentage of the flour weight, which is always 100%. Set your flour, and water, salt and starter fall out by multiplication — 75% hydration means water is three-quarters of the flour weight. For simplicity this tool treats the flour and water you enter as the final dough totals. Strictly, the starter (levain) carries its own flour and water — a 100%-hydration starter is half of each — so a precise baker subtracts the starter’s flour and water from the main dough. The recipe table shows that split so you can adjust if you bake to exact hydration.
Worked example
500 g of flour at 75% hydration: water = 500 × 0.75 = 375 g, salt = 500 × 0.02 = 10 g, starter = 500 × 0.20 = 100 g. Total dough is 500 + 375 + 10 + 100 = 985 g. A 100%-hydration starter of 100 g is 50 g flour plus 50 g water hiding inside that total.
Frequently asked questions
Does the starter’s own flour and water count?
For exact hydration, yes. A 100%-hydration starter is half flour, half water: 100 g of it adds 50 g to your flour total and 50 g to your water total. This simple tool treats your entries as the final amounts and shows the split in the table so you can subtract it from the main mix if you want precise numbers.
What hydration should a beginner use?
Start around 70–75%. It handles well with stretch-and-folds while still opening a nice crumb. Very wet doughs (80%+) are slack and sticky and are easier once you have the shaping down. Whole-grain flours drink more water, so the same percentage feels drier with them.
How much salt is right?
2% of the flour weight is the classic figure — enough to control fermentation and season the loaf without slowing the yeast too much. Below about 1.5% the dough ferments fast and tastes flat; much above 2.5% and the rise drags. Weigh it; a teaspoon of different salts varies a lot by crystal size.
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This calculator is for educational purposes. Double-check important results before acting on them.