Dough Hydration Calculator
Enter a flour weight and a hydration percentage to get the water you need in grams — the baker's-percentage number behind every consistent bread, pizza, and sourdough recipe.
Water from flour and hydration
Enter the flour weight and the hydration percentage and the calculator returns the water in grams: water = flour × hydration% ÷ 100.
Weigh, don't scoop
Baker's percentages are based on weight, not volume — weigh both flour and water in grams so the hydration is accurate every bake.
What is dough hydration?
Water as a percentage of flour
A dough hydration calculator turns two numbers — the flour weight and a hydration percentage — into the water you should add, in grams. Hydration is the heart of baker's percentage: it expresses the water as a share of the flour weight, so a recipe is portable across any batch size. A 70% hydration simply means 70 g of water for every 100 g of flour. Because the percentage is always relative to the flour, you can scale a loaf up or down and keep the same crumb, crust, and handling feel. It is the number behind a workable bread dough, a stretchy pizza base, and an open, airy sourdough.
Enter a flour weight in grams and a hydration percentage to get the water you need in grams instantly.
The water is the flour weight multiplied by the hydration percentage divided by 100.
water = flour × (hydration% ÷ 100)The hydration percentage is the lever: raise it and the dough gets wetter and slacker; lower it and the dough gets stiffer and easier to shape. Because the figure is relative to the flour, the same percentage gives the same dough feel whether you mix 500 g or 5 kg of flour. Weigh both ingredients in grams and the water comes back in grams.
Suppose you are mixing a standard bread dough with 500 g of flour at 70% hydration.
Convert the percentage to a fraction
70 ÷ 100 = 0.70 — the share of the flour weight that becomes water.
Multiply by the flour weight
500 × 0.70 = 350 — flour weight times the hydration fraction.
Read the water
You need 350 g of water for 500 g of flour at 70% hydration.
The hydration percentage tells you what kind of dough you are making. Around 60% is a stiff, low-hydration dough — easy to shape, common in bagels and some pasta — that gives a tighter crumb. Around 70% is the standard sweet spot for everyday bread and pizza: wet enough for an open crumb, dry enough to handle without sticking everywhere. At 80% and above the dough turns wet and slack, the territory of ciabatta, focaccia, and high-hydration sourdough, where the reward is a wildly open, irregular crumb and the cost is sticky, tricky handling that usually needs folds rather than kneading. Moving the percentage by even five points noticeably changes how the dough feels, how it proofs, and how the final crumb looks — so the calculator lets you hit a target hydration precisely instead of guessing.
The formula is exact, but baker's percentage has a couple of conventions worth knowing.
Hydration is relative to flour — and other liquids count
Baker's percentage is always measured against the total flour weight, not the total dough weight, so the percentages can add up to more than 100. This calculator covers the plain water-to-flour figure. If your recipe adds water through a starter, a poolish, milk, eggs, or oil, that liquid also counts toward the real hydration — subtract the water already in your starter or preferment to hit your true target. Salt, by contrast, is a weight, not a liquid, and does not change the water you add.