Sourdough calculator
Most sourdough math goes wrong because the starter is half flour, half water. This calculator counts it, so the hydration you type is the hydration you actually get.
What to mix
| Ingredient | Grams |
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Why the starter changes the numbers
A 100% hydration starter is equal parts flour and water. If a recipe says “500 g flour, 350 g water, 100 g starter”, the real dough contains 550 g flour and 400 g water — 72.7% hydration, not 70%. The calculator works backwards from the dough you want: it finds the total flour, takes the starter’s flour and water out of the amounts you add, and shows the check line so you can see the totals.
Good starting points
- 65–70% hydration is forgiving and easy to shape — start here if you’re new to sourdough.
- 75–80% gives a more open crumb but needs confident handling and strong flour.
- 15–20% starter suits an overnight bulk at cool room temperature; use more starter in a cold kitchen, less in a warm one.
- 2% salt is the standard; 1.8–2.2% is all within normal taste.
- Whole grain flour absorbs more water — add 2–5% hydration if you go above ~30% whole wheat.
Results are estimates for home baking. Fermentation depends on temperature — watch the dough, not the clock. Don’t eat raw dough. Terms