Dough hydration: what it means and how to calculate it
Hydration is the most quoted number in bread baking. It tells you how wet a dough is compared with its flour, and it is simply the water's baker's percentage. Here is how to calculate it properly, including the water hidden in a starter, and how it maps to the German Teigausbeute (TA).
Last reviewed: 2026-10-25
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Hydration is water ÷ flour
Hydration is the weight of the water divided by the weight of the flour, times 100. A dough with 1,000 g of flour and 700 g of water is at 70% hydration. King Arthur Baking's pro reference defines it the same way: the liquid percentage, based on the flour weight. In other words, it is the water line of a formula written in baker's percentages.
Because it is measured against the flour and not the whole dough, a 70% dough is not 70% water. Its water share of the total weight is lower: in a dough of 100% flour, 70% water, 2% salt and 1% yeast, the water is 70 ÷ 173 = 40.5% of the dough.
The Baker's Percentage Calculator shows the hydration automatically when one of your ingredients is named water.
Typical hydration by dough type
Wikipedia's baker percentage article groups doughs like this:
| Dough | Hydration |
|---|---|
| Very stiff | under 57% |
| Stiff to firm | 57–65% |
| Soft | 65–70% |
| Soft to slack | 70–80% |
| Bagels and pretzels | about 50–57% |
| Breads and rolls | about 58–65% |
| Drop batter | about 95% |
| Pour batter | about 190% |
Source: Wikipedia, "Baker percentage". Higher hydration produces more and larger holes, as in baguettes and ciabatta.
Use the table to sanity-check a recipe. Keep in mind that the same percentage can feel different with a different flour: flours absorb water differently, and baker's percentages say nothing about the flour itself. When you switch flour, expect to adjust the water.
Changing the hydration of a formula
Because hydration is a percentage of the flour, changing it only changes the water. Nothing else in the formula needs recalculating.
- Find the flour weight. Say 1,000 g, currently with 650 g of water (65%).
- Multiply the flour by the new hydration. For 72%: 1,000 × 0.72 = 720 g of water.
- The difference is what to add: 720 − 650 = 70 g more water.
Going the other way, 1,000 g of flour at 60% needs 600 g of water, 50 g less than at 65%. If you want to change hydration without changing the dough weight, recalculate the flour from the new total percentage. At 65% water, 2% salt and 1% yeast the formula totals 168%, so 1,000 g of flour makes 1,680 g of dough. At 72% it totals 175%, and the same 1,680 g of dough needs 1,680 ÷ 1.75 = 960 g of flour and 960 × 0.72 = 691 g of water.
Change hydration a few percent at a time and bake between changes, so you can see what each step does to the dough and the crumb.
Counting the water in a starter or poolish
This is where most hydration figures go wrong. A levain, sourdough starter or poolish is part flour and part water, and both belong in the dough's totals. King Arthur Baking describes a poolish as equal weights of flour and water (100% hydration), and levain as anywhere from 50% to 125% hydration.
Worked example. The final mix is 900 g flour, 600 g water, 20 g salt and 200 g of levain kept at 100% hydration. That levain is 100 g flour and 100 g water.
| Flour | Water | |
|---|---|---|
| Final mix | 900 g | 600 g |
| Inside the levain | 100 g | 100 g |
| Overall | 1,000 g | 700 g |
Overall hydration = 700 ÷ 1,000 = 70%. Counting only the final mix would give 600 ÷ 900 = 66.7%.
Check the salt against the overall flour too: 20 ÷ 1,000 = 2%. A stiff levain at 50% hydration splits 2:1, so 150 g of it is 100 g flour and 50 g water. To split any preferment, divide its weight by (1 + hydration): 150 ÷ 1.5 = 100 g flour, and the rest is water. The preferments guide covers poolish and biga the same way.
Milk and other liquids
Recipes sometimes quote hydration for water only and sometimes for all liquids. Neither is wrong, but say which one you mean. Milk, eggs and butter all contain water, but none of them is pure water, so adding their full weight to the water overstates the real hydration. An exact figure needs the water content of the specific product, which varies, so we do not give a single number for it here.
German bakers handle this with the Teigausbeute, described next, which counts the added liquid (water and/or milk) by weight.
Teigausbeute (TA): the German way to write hydration
German recipes often give a TA (Teigausbeute, dough yield) instead of a hydration. German Wikipedia defines it as the amount of dough obtained from 100 parts of flour after mixing in the liquid:
TA = dough weight × 100 ÷ flour weight
For a dough of just flour and liquid, the TA is 100 plus the liquid percentage. Wikipedia's example: 10 kg flour and 5 kg water give TA 150, which is 50% hydration. TA 170 is 70% hydration, TA 180 is 80%.
There are two versions. Netto-TA counts only the flour and the added liquid (water and/or milk). Wikipedia's bread roll example adds 5.8 kg of milk to 10 kg of flour for a Netto-TA of 158. Brutto-TA counts every ingredient, including eggs, sugar, salt, fat and yeast. Typical Netto-TA values quoted by Wikipedia (from Loderbauer, 2008):
| Bread | Netto-TA | Hydration equivalent |
|---|---|---|
| Pretzel (Brezel) | 150 | 50% |
| Wheat bread / toast bread | 154–158 | 54–58% |
| Bread rolls (Brötchen) | 156–158 | 56–58% |
| Baguette | 165 | 65% |
| Ciabatta | 170–175 | 70–75% |
| Rye bread | 175–178 | 75–78% |
| Wholemeal / coarse meal bread | 176–180 | 76–80% |
Hydration equivalent = TA − 100, valid for a flour-and-liquid (Netto) TA.
As the article puts it, the lower the TA, the firmer the dough. If a German recipe gives a TA, subtract 100 to get the hydration and you can work with it in any baker's percentage tool.
Hydration and bake loss
A wetter dough has more water to lose in the oven and while it cools. Busby's Bakery puts total bake loss at 10–25% of the dough weight, with long, thin, crusty breads such as baguettes losing the most. Higher hydration, a smaller or longer loaf and a darker or longer bake all push the loss up. If you sell by weight, measure the loss again with the Bake Loss Calculator whenever you change a formula's hydration.
Frequently asked questions
How do I calculate dough hydration?
Divide the water weight by the flour weight and multiply by 100. 700 g water and 1,000 g flour is 70%. Include the water and flour inside any starter or preferment.
What hydration is a good starting point?
Wikipedia puts breads and rolls at about 58–65% and soft doughs at 65–70%. Doughs above 70% are slack and harder to handle.
How does TA relate to hydration?
For a flour-and-liquid dough, TA = 100 + hydration. TA 165 is 65% hydration.
Does milk count toward hydration?
It counts as liquid in the German Netto-TA, but milk is not pure water, so treating its full weight as water overstates the true hydration. State whether your figure counts water only or all liquids.
Why does my 75% dough feel different from someone else's?
Different flours absorb different amounts of water, and baker's percentages do not describe the flour. The same percentage can give a stiffer or slacker dough with another flour.
Baker's Percentage Calculator — Turn a dough formula into baker's percentages (flour = 100%), or go the other way: percentages + target flour weight → exact ingredient weights.
Open the Baker's Percentage Calculator →Sources
- Wikipedia — Baker percentage — hydration ranges by dough type, batters
- Wikipedia (de) — Teigausbeute — TA formula, Netto/Brutto-TA, typical TA values (Loderbauer 2008)
- King Arthur Baking — Baker's percentage (pro reference) — hydration = liquid as a percentage of flour
- King Arthur Baking — Preferment (pro reference) — poolish 100% hydration, levain 50–125%
- Busby's Bakery — How much weight does bread lose when baked? — bake loss 10–25%
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