Baker's math, made human
Sourdough Hydration Calculator
Find the true hydration of any dough, including the flour and water hiding inside your starter, plus baker's percentages and exact water tweaks for the texture you want.
Your dough
Enter your recipe in grams; the calculator includes the flour and water hidden inside your starter, so the result is your true hydration.
True hydration (incl. starter)
70%
Medium hydration
Total flour
500 g
Total water
350 g
Dough weight
860 g
Salt (baker's %)
2.0%
| Ingredient | Grams | % of flour |
|---|---|---|
| Added flour | 500 g | 100% |
| Added water | 350 g | 70% |
| Starter | 0 g | 0% |
| Salt | 10 g | 2% |
Add 25 g of water to reach 75%.
What is sourdough hydration?
Hydration is the water to flour ratio of your dough, written as a percentage. A 70% dough has 70 g of water for every 100 g of flour. It sounds simple, but it shapes almost everything about your bread, from crumb to crust to how the dough feels in your hands.
Most calculators only count the water you pour in. That misses the flour and water already inside your starter. A starter at 100% hydration is half flour and half water by weight, so a recipe with 500 g flour, 350 g water and 100 g starter is really72.7% hydrated, not 70%. That difference is enough to turn a firm dough into a sticky one. This calculator adds the hidden flour and water from your starter so you see the true number.
New to this? The hydration guide walks through the math with a worked example, and the hydration levels chartshows what each percentage feels and bakes like.
How to get your true hydration in 30 seconds
- Enter your flour, water, starter and salt in grams. Leave starter at 0 if you are not using one.
- Check the big percentage at the top of the results card. That is your true hydration including the starter.
- Use the tweak slider to see exactly how much water to add or remove for your target texture.
Prefer to work backwards? Open reverse mode, enter your target hydration and total flour, and the calculator tells you the water you need.
Hydration levels at a glance
What each hydration range means for 500 g of flour (water shown per 100 g of flour).
| Level | Hydration | Water / 100 g flour | Feels like | |||
|---|---|---|---|---|---|---|
| Low hydration | 0–65% | 0–65 g | Stiff, easy-to-handle dough with a tight crumb. Great for beginners and shaped loaves like bagels. | Stiff, easy-to-handle dough with a tight crumb. Great for beginners and shaped loaves like bagels. | ||
| Medium hydration | 66–74% | 66–74 g | The classic sandwich-loaf range. Manageable by hand, open enough crumb for everyday bread. | The classic sandwich-loaf range. Manageable by hand, open enough crumb for everyday bread. | ||
| High hydration | 75–82% | 75–82 g | Slack, sticky dough with an open, airy crumb. Expect coil folds and a bench scraper. | Slack, sticky dough with an open, airy crumb. Expect coil folds and a bench scraper. | ||
| Very high hydration | 83–100+% | 83–100+ g | Focaccia territory. Almost batter-like; shaping is done in the pan or with heavy flouring. | Focaccia territory. Almost batter-like; shaping is done in the pan or with heavy flouring. | ||
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Quick answers
Why is my dough 72% hydrated when the recipe says 70%?
Your starter adds flour and water that the recipe does not count. With 500 g flour, 350 g water and 100 g starter at 100% hydration, you really have 550 g total flour and 400 g total water. That works out to about 72.7%.
What hydration should a beginner use?
Try 65 to 70%. The dough stays firm enough to shape by hand, it holds its shape during proofing, and it forgives small mistakes while you learn folds and fermentation. Move up once shaping feels easy.
What does "100% hydration starter" mean?
You fed the starter equal weights of flour and water. So 100 g of that starter holds about 50 g flour and 50 g water. That hidden water is why it changes your true hydration.
How is true hydration different from recipe hydration?
Recipe hydration divides added water by added flour. True hydration divides all water by all flour, including what lives inside the starter. The recipe number is almost always a bit low.
Do I need a different hydration for whole wheat?
Whole wheat and rye soak up more water but build weaker gluten. If you swap in 20 to 30% whole wheat, keep hydration around 68 to 72% at first, then raise it only if the dough still feels dry.