Sourdough Hydration Calculator
Calculate the hydration percentage of your sourdough bread dough.
Adjust flour and water ratios for the perfect crumb texture.
Dough hydration is the ratio of water to flour in a bread recipe, expressed as a percentage. It is one of the most important variables in sourdough baking because it directly determines the texture, crumb structure, crust, and handling properties of your bread.
The formula: Hydration (%) = (Total Water ÷ Total Flour) × 100
For example, if your recipe calls for 400g of flour and 300g of water: Hydration = (300 ÷ 400) × 100 = 75%
Hydration levels and their effects:
| Hydration | Dough Type | Crumb | Handling |
|---|---|---|---|
| Under 60% | Stiff | Tight, dense | Very easy |
| 60–70% | Standard | Moderate, even | Easy |
| 70–80% | Wet | Open, holey | Moderate |
| 80–90% | Slack | Very open | Difficult |
| 90%+ | Ciabatta-style | Extremely open | Expert only |
Why hydration matters: Higher hydration doughs develop more complex flavors and produce the characteristic “open crumb” (large air pockets) prized in artisan sourdough. They are also much harder to shape. Start somewhere in the 65 to 70% band, where the dough still behaves like dough, and work up once shaping stops being a fight. Chasing an open crumb at 85% before you can handle 70% is the fastest way to a flat loaf.
Starter hydration: Your sourdough starter also has a hydration level of its own, usually 100%, meaning equal parts flour and water by weight. This calculator counts the flour and water inside your starter toward the totals, because they end up in the loaf like everything else. Leave them out and the number you calculate is not the number you baked.
Note: This calculator uses baker’s math, where every ratio is relative to the flour weight. Salt and any additions are quoted the same way, as a percentage of flour. That is what makes scaling a recipe up or down trivial: change the flour and everything else follows.
Practical tip: When increasing hydration, add water gradually during mixing rather than all at once. The flour absorbs water slowly; rushing it leads to sticky, unworkable dough.
Units note: the figures here are in grams, which is what almost every bread recipe uses because baking rewards weighing over measuring. Hydration itself is a ratio, so it comes out the same whatever unit you weigh in. If your recipe is in ounces, the percentage will still be right, but the gram amounts the calculator suggests adding or removing will not be, so convert first.
How we build and check this calculator
This calculator runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
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