Sourdough Hydration Calculator
Get your dough's true hydration — with the flour and water inside your starter counted correctly, at any starter hydration. Plus salt percentage, prefermented flour and the exact water for a target hydration.
| Total flour (incl. starter) | — |
| Total water (incl. starter) | — |
| Salt (baker's %) | — |
| Prefermented flour | — |
| Total dough weight | — |
A 100%-hydration starter is equal parts flour and water by weight, so 100 g of it contributes 50 g flour + 50 g water. Keep a stiff starter? Set its hydration and the split adjusts.
How sourdough hydration is calculated
Hydration is a baker's percentage: total water ÷ total flour × 100. The catch with sourdough is that your starter is part flour, part water. For a starter of weight S at hydration h:
starter flour = S ÷ (1 + h/100) · starter water = S − starter flour
So 500 g flour + 350 g water + 100 g of 100%-hydration starter is really 550 g flour and 400 g water — 72.7% hydration, not the 70% you'd get by ignoring the starter. The difference grows with bigger starter amounts and stiff starters.
What hydration should you aim for?
| Hydration | What you get |
|---|---|
| 65–68% | Beginner-friendly: easy to shape, tighter crumb, good sandwich loaves |
| 70–75% | The classic range for everyday artisan sourdough |
| 76–82% | Open, airy crumb; sticky dough that needs confident handling |
| 83%+ | Ciabatta-style very wet doughs; usually pan-baked or heavily floured |
Flour matters as much as the number: whole-wheat and rye absorb more water, and strong bread flour handles high hydration far better than all-purpose. When trying a new flour, change hydration a few points at a time.
Frequently asked questions
What is sourdough hydration?
Hydration is the total water in your dough expressed as a baker's percentage of the total flour — including the water and flour inside your starter. A dough with 550 g total flour and 400 g total water is at 400 ÷ 550 × 100 ≈ 73% hydration. Higher hydration gives a more open, moist crumb; lower hydration gives a tighter crumb and easier-to-handle dough.
Do you include the starter when calculating hydration?
Yes — for the true (overall) hydration you must count the starter's contents. A starter kept at 100% hydration is half flour and half water by weight, so adding 100 g of it adds 50 g flour and 50 g water to the dough. Ignoring the starter overstates your hydration on stiff starters and understates the flour in the recipe. This calculator splits the starter for you at whatever hydration you keep it.
What hydration should sourdough bread be?
Most sourdough loaves are between 65% and 80% hydration. Around 65–70% is the easiest to shape and a good starting point; 75%+ gives a more open crumb but a stickier, harder-to-handle dough. Whole-wheat and rye flours absorb more water, so doughs with them are usually pushed a few points higher.
What hydration is a sourdough starter?
Most bakers keep their starter at 100% hydration — fed with equal weights of flour and water. Stiff starters (like an Italian lievito madre) are kept around 50–65% hydration, and some bakers use liquid starters above 100%. Enter whatever ratio you feed yours; the math adjusts automatically.
How much salt goes in sourdough bread?
Salt is typically about 2% of the total flour weight (a range of 1.8–2.2% is common) — that's 10–11 g for a dough with 550 g of total flour. The calculator shows your salt percentage against total flour, including the flour in the starter.
How do I change my dough's hydration?
Enter your target percentage in the calculator and it returns exactly how much water the recipe needs: required water = target % × total flour − water already in the starter. Add the difference (or hold back water during mixing if you're above target).
Building the full formula? Use the baker's percentage calculator. Swapping yeast types in a hybrid dough? See the yeast converter. Weighing flour from cups? Try the bread flour or whole wheat flour converters.