Dough Hydration Calculator
Find true dough hydration with the flour and water in your starter counted, or work out how much water a target hydration needs.
Hydration, with the starter counted
Hydration is the water weight divided by the flour weight, as a percentage. A starter at hydration H% weighing S grams holds S × 100 ÷ (100 + H) grams of flour and the rest is water.
Example: 400 g flour + 300 g water + 200 g of 100% starter. The starter adds 100 g flour and 100 g water, so total flour is 500 g, total water 400 g and hydration 80%.
Reaching a target hydration
Enter a target and the calculator returns the water to add: target × total flour − the water already in the starter. The adjustment shows how far that is from the water you entered.
FAQ
What hydration is a normal bread dough?
Many sandwich doughs sit around 60–65% and rustic loaves around 70–80%. Higher values give a more open but stickier dough. Flour type changes how wet a given percentage feels.
What if I do not know my starter’s hydration?
A starter fed with equal weights of flour and water is 100%. Leave it at 100 unless you feed it differently.
Does this change salt or yeast?
No. It only handles flour and water. Use the baker’s percentage calculator for the rest of the formula.
Other Languages
References
How we make sure
We check this tool with the automated test suites linked below. Example checks are shown in their original language.
- Verification method
- Check plain hydration, 100% and 50% starters that contribute flour and water, and the water needed for a target hydration.
- Comparison reference
- Hand arithmetic from the King Arthur hydration definition (water ÷ flour); no independent calculator implementation was run.
- Verification scope
- Only these samples and boundaries are checked; this does not prove correctness for every input or guarantee a bake.
Test source and cases (select a file to read it)
-
baker-tools.test.js
- hydration: plain flour and water, no starter
- hydration: a 100% starter contributes equal flour and water
- hydration: a 50% stiff starter splits one third water and two thirds flour
- hydration: target hydration returns the water to add and the adjustment
These checks cover the listed examples and boundaries, not every possible input. Round trips and checks using the same library are not independent verification.