Equal flour and water
100 g starter = 50 g flour + 50 g waterWith 500 g flour and 350 g water added separately, the true hydration is 400 ÷ 550 × 100, or 72.7%.
← All calculatorsSOURDOUGH BAKER'S MATH
Sourdough Hydration Calculator
Calculate your dough's true hydration—including the flour and water hidden inside your starter or levain.
THE COMPLETE FORMULA
What sourdough hydration really measures
Dough hydration is total water divided by total flour, expressed as a percentage. For sourdough, “total” includes both parts of the starter. Ignoring them can make a recipe's stated hydration misleading.
A stiff starter
100 g starter = 62.5 g flour + 37.5 g waterThe same main dough becomes 387.5 ÷ 562.5 × 100, or 68.9% hydration.
READING THE NUMBER
Hydration ranges are context, not a guarantee
| Hydration | Typical dough feel | What to expect |
|---|---|---|
| Below 65% | Firm | Easier shaping and a tighter crumb in many wheat doughs. |
| 65–75% | Moderate | A common working range for hearth-style sourdough. |
| 75–80% | Wet | Stickier handling with potential for a more open crumb. |
| Above 80% | Very wet | Usually requires suitable flour and confident handling. |
Flour protein, whole-grain content, milling, inclusions, and technique all change how two doughs at the same hydration feel.
COMMON QUESTIONS
Sourdough hydration FAQ
How do you calculate sourdough hydration?
Divide the total water by the total flour and multiply by 100. Both totals should include the flour and water contained in the starter or levain.
Should sourdough starter count toward hydration?
Yes. For overall dough hydration, split the starter into its flour and water components and add each component to the matching total.
What does 100% hydration starter mean?
A 100% hydration starter contains equal weights of flour and water. For example, 100 grams of starter contains 50 grams of flour and 50 grams of water.
Does salt count in sourdough hydration?
No. Hydration compares water with flour. Salt is normally expressed separately as a percentage of total flour weight.
Do milk, eggs, and other liquids count as water?
Professional bakers may treat milk, juice, beer, or similar liquids as hydration, but enriched ingredients also contain fat and solids. This calculator intentionally uses only the water field and starter water so the result stays transparent.
Research-based sources
- King Arthur Baking: Baker's Percentage — baker's math, hydration, and overall percentages for preferments.
- King Arthur Baking: Hydration in bread dough, explained — hydration formula and practical interpretation.