Cooking

Dough hydration calculator

Starter included, which is where most calculators get it wrong.

Reviewed September 19, 2026FreeNo sign-up≈ 2 minutes

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Enter your measurements.
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Rather see a worked case? Press “Load example” and change any value afterwards.

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With the hydration set, the yeast decides how long it takes to rise.

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Where each number comes from Conversion constants are exact; densities and coverage rates come from cited sources; everything else is an assumption you can change. Methodology · Sources and updates

How to use it

Enter the flour weight.
Choose whether you have the water and want the percentage, or the reverse.
If you use a starter, enter it in the advanced options with its hydration.
The result splits out the flour and water your starter contributes.

How it is calculated

Hydration is a division, with one catch named sourdough starter:

hydration = total water / total flour x 100 starter flour = starter / (1 + starter hydration / 100) starter water = starter - its flour

A 100 % hydration starter is half flour, half water. Add 100 g of it to a formula with 500 g of flour and 350 g of water and the real hydration is not 70 % but (350 + 50) / (500 + 50) = 72.7 %.

That three-point gap is why two bakers working from the same written recipe end up with different doughs.

Worked example

500 g flour, 350 g water and 100 g of 100 % starter:

Starter: 50 g flour + 50 g water
Total flour: 500 + 50 = 550 g
Total water: 350 + 50 = 400 g
Hydration: 400 / 550 = 72.7 %

Good to know

Flours absorb differently. A strong or wholemeal flour takes more water than a weak white one: the same 70 % gives different doughs.
Rough ranges. Under 60 % is stiff dough (bagels); 60-70 %, pan breads and manageable doughs; 70-80 %, open crumb; over 80 %, ciabatta territory.
Hydration is not a score. More water is not better bread: it is different bread, and harder to handle.
Only water counts. Milk, egg and oil hydrate differently; classic hydration counts water alone.

Frequently asked questions

What is dough hydration?

The weight of the water divided by the weight of the flour, as a percentage. A dough with 500 g flour and 350 g water is at 70 % hydration.

How does a starter affect hydration?

It brings its own flour and water, so it raises the real hydration. With 100 g of 100 % starter, a formula that looks like 70 % is actually 72.7 %.

How much water is a 75 % dough?

375 g for every 500 g of flour. If you use a starter, subtract the water it already contributes.

What hydration should I aim for?

It depends on the bread and your handling skills. 65-70 % is a comfortable starting range; above 80 % the dough is hard to handle by hand.

Does milk count as water?

Not in the classic notation: hydration refers to water. Milk is listed as its own ingredient even though it adds moisture.

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