Hydration — water as a percentage of flour — is the single number that tells you most about how a dough will feel and bake. Enter the flour and water from any recipe to see its hydration, or pick a target and get the exact water to add. Starters and preferments are split into their flour and water so the number you see is the true overall hydration, and any other ingredient gets its baker's percentage.
For full recipes, the sourdough calculator scales a loaf around your starter and the pizza dough calculator builds dough for any number of pies. Converting cups to grams first? The unit converter handles weights and volumes. The math behind the numbers, including how a starter shifts the real hydration, is in baker's percentages, hydration, and starters.
Frequently asked questions
How do you calculate bread hydration?
Divide the weight of the water by the weight of the flour and multiply by 100. A dough of 500 g flour and 350 g water is 70 % hydration. Always weigh rather than measure by cups — a cup of flour can vary by 20 % or more depending on how it is scooped. If your recipe lists grams, this calculator gives the hydration instantly; in the other mode it tells you how much water to add to reach a target hydration.
How do starters, poolish, and biga change hydration?
A preferment is just flour and water mixed ahead of time, so its flour and water belong in the totals. A 100 % poolish or levain is half of each; a biga at 50 % is two parts flour to one part water. Tick the preferment box and enter its weight and hydration: the calculator splits it, adds it to the totals, and reports the true overall hydration — or, in target mode, subtracts its water from what you need to add.
What hydration is right for each bread?
As a rough guide: bagels and pretzels are stiff at 50–58 %; pizza and French bread sit around 60–65 %; sandwich loaves 65–70 %; country sourdough 70–75 %; ciabatta and focaccia 75–85 %; and pan-baked focaccia or Roman-style pizza can go higher still. The table under the calculator highlights the band your dough falls into. Flour matters too — whole wheat and high-protein bread flour absorb more water than all-purpose, so the same percentage feels stiffer. When trying a new flour, start at the low end of the range and add water a spoonful at a time.
What are baker’s percentages for salt and yeast?
Every ingredient is a percentage of the total flour weight. Typical lean bread uses 1.8–2.2 % salt, 0.5–1.5 % instant yeast (less for long ferments), and 0–5 % oil or butter; enriched doughs add sugar, eggs, and more fat. Add any ingredient in the “Other ingredients” list and its baker’s percentage appears next to it, calculated against total flour including any preferment. That makes it easy to compare two recipes of different sizes: once both are in percentages, you can see at a glance which is saltier, richer, or more heavily yeasted, and scale either one to any batch size.
Do milk and eggs count as water?
Not in this calculator, which only counts the water you enter. Milk is roughly 87 % water and whole eggs about 75 %, so enriched doughs behave wetter than their water percentage suggests. If you want a rough “effective hydration,” add 0.87 × the milk weight and 0.75 × the egg weight to the water field. Butter is about 16 % water as well. Fat and sugar also soften dough, so a brioche at a modest “hydration” still feels rich and slack — judge enriched doughs by feel as much as by numbers.