Dough Hydration Calculator

Get the water weight for a target hydration, check the hydration of your own recipe, or fold in your sourdough starter's water and flour.

How it works

Pick a mode: enter a flour weight and a target hydration percentage to get the water weight, or enter both flour and water from a recipe you already have to see what hydration it actually is. Hydration is just water divided by flour, expressed as a percentage: 350 g of water against 500 g of flour is 70% hydration. Every other ingredient in a bread recipe (salt, starter, oil, seeds) gets described the same way, as a percentage of the flour weight, which is why bakers call this system baker's percentages.

Worked example: 500 g of flour at a 75% target hydration needs 375 g of water (500 × 0.75). If you're feeding a sourdough starter, add its weight to get an effective hydration. A starter fed 1:1 by weight sits at 100% hydration itself, so half of what you scoop into the bowl is water and half is flour. Add 100 g of that starter to the 500 g flour and 350 g water above and the effective hydration works out to 72.7%, a bit higher than the 70% the flour and water alone would suggest, because the starter is quietly adding both flour and water to the mix.

FAQ

What does 65% vs 75% vs 85% hydration actually feel like?

At 65%, the dough is stiff and easy to shape by hand. It's a forgiving place to start if you're new to bread. At 75%, the dough gets tackier and slacker; it wants stretch-and-folds instead of kneading and rewards you with a more open crumb. At 85% and up, you're in ciabatta-and-focaccia territory: the dough behaves more like a thick batter than something you can shape on a counter, and most bakers work it with wet hands or a bowl scraper instead of trying to knead it.

Does higher hydration always mean a better loaf?

No. More water makes a more open, chewier crumb up to a point, but it also makes the dough harder to shape and more likely to spread flat instead of holding its shape in the oven. Flour strength matters too: a weaker all-purpose flour can struggle to hold 80%+ hydration, while a strong bread flour handles it fine. Start around 70 to 75% for your first few loaves and adjust from there.

Why does the starter change my "real" hydration?

Because a mature starter is itself flour and water, usually at 100% hydration if you feed it 1:1. Ignore it and you'll undercount how much water is really in the dough, which is why a recipe can look like 70% hydration on paper but handle closer to 73% once the starter is folded in.

Can I use this for enriched doughs with milk, butter, or eggs?

Roughly. Milk is mostly water, so a recipe built on milk instead of plain water will read a little lower on this calculator than it actually handles, since milk's fat and solids add body without adding water one for one. Treat the number as a close estimate for enriched doughs rather than an exact one.

For more on the math behind these numbers, see baker's percentages explained, what dough hydration actually changes, and how to feed and maintain a sourdough starter.