Sourdough Calculator
Flour, water, starter and salt in grams — from a flour weight or a target dough weight
Set the hydration, starter and salt you want and the calculator works out how much flour and water to add once the starter's own flour and water are counted. It also checks any recipe's true hydration.
A 75% hydration, 20% starter, 2% salt loaf at different sizes
| Total flour | Flour to add | Water to add | Starter | Salt | Dough |
|---|---|---|---|---|---|
| 400 g | 360 g | 260 g | 80 g | 8 g | 708 g |
| 500 g | 450 g | 325 g | 100 g | 10 g | 885 g |
| 750 g | 675 g | 488 g | 150 g | 15 g | 1328 g |
| 1000 g | 900 g | 650 g | 200 g | 20 g | 1770 g |
Starter flour = starter ÷ (1 + starter hydration). Flour to add = total flour − starter flour; water to add = total flour × hydration − starter water. Method: King Arthur Baking, Baker's percentage.
Frequently asked questions
Does the starter count towards hydration?
Yes. A 100% starter is half flour and half water, and both end up in the loaf. 450 g flour, 325 g water and 100 g starter is 500 g flour and 375 g water in total: 75% hydration.
How much salt goes in sourdough?
About 2% of the total flour weight — 10 g for 500 g of flour.