Sourdough hydration calculator
Enter your recipe’s flour, water and starter to see its true hydration. The flour and water inside the starter are counted, so you get the number your dough actually feels like.
Milk or other liquids
Whole milk is about 87% water.
See how much water to use instead to reach a different hydration.
Your dough
- True hydrationstarter counted
- 75%
- As recipes state itwater ÷ added flour
- 72.2%
- Total flour
- 500g17.6 oz
- Total water
- 375g13.2 oz
Starter 20% of flour, salt 2%
For 75% use 325 g water (no change)
What hydration means
Hydration is the weight of water divided by the weight of flour. 375 g of water with 500 g of flour is 75% hydration. It tells you how wet a dough is before you touch it, and it’s the easiest way to compare two recipes.
Two numbers, same recipe
Many recipes state hydration as water over the flour you add, ignoring the starter. The calculator shows that number too, but the true hydration is the one that matches your dough. For a recipe of 450 g flour, 325 g water and 100 g of 100% starter:
- As stated:
325 ÷ 450 = 72.2% - True:
(325 + 50) ÷ (450 + 50) = 75%
How hydration feels
| True hydration | What the dough is like |
|---|---|
| 60–67% | Firm and smooth. Easy to shape, tight even crumb. Sandwich loaves and bagels. |
| 68–74% | Soft and slightly tacky. A good place to learn shaping. |
| 75–80% | Sticky and stretchy. Open, glossy crumb with practice. |
| 80% and up | Slack and loose. Needs strong flour, good folds and confident shaping. Focaccia territory. |
Changing the hydration of a recipe
Set a target hydration and the calculator tells you how much water to use instead. If you’re unsure, hold back 20–30 g of the water when you mix and add it in small splashes while you work the dough. To build a recipe from scratch at a given hydration, use the sourdough calculator.
Questions bakers ask
Is 75% hydration high for sourdough?
It’s in the middle. Most country loaves sit between 70% and 78%. Below 68% the dough is firm and easy to handle; above 80% it is slack and takes practice to shape.
Why does my dough feel wetter than the recipe says?
Usually because the recipe’s hydration ignores the starter. 100 g of a 100% hydration starter adds 50 g of water, which raises a 500 g flour dough by several points. Different flours also absorb different amounts of water.
Does milk count as water?
Mostly. Whole milk is about 87% water, so 100 g of milk adds about 87 g of water. Enter it under Milk or other liquids.
What hydration is my starter?
If you feed it equal weights of flour and water, it is 100% hydration. Feeding 50 g of flour with 25 g of water gives a stiff starter at 50%.