Sourdough Hydration Calculator
Quick answer: Sourdough hydration is total water divided by total flour, counting the starter's halves: 500 g flour, 350 g water and 100 g of 100%-hydration starter works out to about 73% — with salt at 2% of the flour (11 g).
Hydration is the number that explains why one loaf is a sandwich brick and another is all open crumb. Enter your flour, water and starter, and we'll compute the true hydration — counting the flour and water hiding in your starter.
What hydration gets you
| Hydration | Dough feel | Typical bakes |
|---|
| 60–65% | Stiff, easy to shape | Bagels, pretzels |
| 65–70% | Standard | Sandwich loaves |
| 70–75% | Medium-slack | Everyday sourdough |
| 75–85% | Slack, wet | Ciabatta, open crumb |
| 85%+ | Pourable | Focaccia |
How it works
Bakers describe dough in baker's percentages — every ingredient as a percentage of the flour weight — and hydration is the big one: total water divided by total flour. The trap is the starter, which is itself flour and water. A starter at 100% hydration is half of each, so the tool splits it (at whatever hydration yours runs), adds each half to your totals, and reports the dough's true hydration plus the standard 2%-of-flour salt. Chase a number you can handle rather than the wettest crumb on the internet: an honest 70% bakes better bread than a mishandled 85%.
Frequently asked
How do I calculate sourdough hydration?
Divide total water by total flour — including what's in the starter. A 100 g starter at 100% hydration contributes 50 g flour and 50 g water. So 500 g flour, 350 g water and 100 g starter is 400 ÷ 550 ≈ 73% hydration.
What hydration should a beginner use?
Start at 65–70%. It's forgiving to shape and still bakes an open, moist loaf. Push toward 75%+ only once your shaping and tension are solid — wet dough punishes hesitation.
How much salt goes in sourdough?
About 2% of the total flour weight — 11 g for a 550 g-flour dough. The calculator shows it automatically. Much less tastes flat; much more slows fermentation.
Does flour type change the hydration I should use?
Yes. Whole wheat and rye drink far more water than white bread flour — a 75% whole-wheat dough handles like a 68% white one. Add 5–10% hydration when going heavily whole-grain.
What hydration is my starter?
Whatever you feed it. Equal weights of flour and water is 100% — the common default. If you feed 1 part water to 2 parts flour, it's a 50% stiff starter; set that in the calculator and the math adjusts.
Why does my wet dough spread flat?
High hydration demands strong gluten and confident shaping. Build strength with folds during bulk, shape with a fast, tight motion, and bake in a preheated Dutch oven — or just drop 5% hydration and enjoy taller loaves.
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