Sourdough Hydration Calculator: Include Your Starter
A starter-aware sourdough calculator that separates the flour and water inside your starter before calculating true dough hydration and baker’s percentages.
True hydration includes the starter
A 100% hydration starter contains equal weights of flour and water. If a formula uses 100 g of that starter, it adds 50 g flour and 50 g water to the final dough.
Ignoring those contributions can make the displayed hydration differ from the dough you actually mixed. This calculator separates the starter first, then divides total water by total flour.
Hydration is a description, not a grade
Higher hydration often produces a looser, stickier dough, while lower hydration is usually firmer. Flour type, protein, milling, temperature, mixing, and technique all change how the same percentage behaves.
Prefermented flour shows how much of the formula’s total flour is already in the starter. It is useful formula context but does not predict fermentation by itself.
Examples
Starter changes the headline number
Input
500 g flour, 350 g water, 100 g starter at 100%
Show result
Result
550 g total flour, 400 g total water, and 72.73% true hydration
Calculate salt by flour
Input
550 g total flour at 2% salt
Show result
Result
11 g salt
Frequently Asked Questions
What does 100% starter hydration mean?
It means the starter contains equal weights of flour and water.
Should starter count toward hydration?
Yes. Its flour and water are part of the final dough, so true hydration includes both.
What hydration is best?
There is no universal best percentage. Flour and technique matter, so use the number to record and compare your own formulas.
References
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