Baker’s-percentage hydration from flour and water grams — plus what your dough’s number actually means.
Ask a baker why one loaf has a tight, even crumb and another is full of wild holes, and the answer is usually a single number: hydration. It is the weight of the water expressed as a percentage of the flour — 350 grams of water in 500 grams of flour is 70% hydration — and it predicts almost everything about how a dough behaves. Our free Bread Hydration Calculator computes that number from your flour and water weights and classifies the dough: stiff, standard, high, or very high.
Hydration is written in baker’s percentages, the professional system where flour is always 100% and every other ingredient is a fraction of it. That convention is what makes recipes scalable — 70% hydration is 70% whether you are baking one loaf or forty — and it is why serious bread recipes are written in grams. A cup of flour can weigh anywhere from 120 to 150 grams depending on the scoop; 500 grams is 500 grams.
Enter your flour and water below for the headline number (the default 500 g / 350 g lands at 70.0%, high hydration at the top of the standard range), then read on for how hydration shapes crumb and handling, the formula with worked examples, practical scaling scenarios, the five mistakes that sink doughs, and answers to the questions home bakers ask most.
Water does two jobs in bread dough: it hydrates the flour proteins so they can link into gluten, and it hydrates the starches so they gelatinize in the oven’s heat. More water means more mobile gluten — the dough stretches further, traps bigger gas bubbles from the yeast, and bakes into an open, airy crumb with a crackling crust. Less water means a tighter gluten network, a fine even crumb, and a dough you can shape with confidence.
The four bands describe genuinely different doughs. Stiff doughs (below 60%) — bagels, pretzels, many sandwich loaves — are firm, hold their shape aggressively, and ferment a touch slower. Standard doughs (60–70%) are the everyday workhorses: soft but manageable, the zone of classic sandwich bread and pizza dough. High hydration (70–80%) is artisan territory — ciabatta, focaccia, open-crumb sourdough — slack, sticky, and handled with folds rather than kneading. Very high (above 80%) is specialist dough: pourable, dramatic, and unforgiving.
Flour is not a constant, which is the subtlety beginners miss. A strong bread flour at 13% protein drinks more water than a 10% all-purpose; whole wheat’s bran and germ are thirsty too. That is why hydration is a property of the flour-plus-water pair, not a universal truth — 70% with one flour can feel like 65% with another. Professionals adjust by feel within a few percent; the calculator gives you the starting number to adjust from.
Handling follows the number. Stiff and standard doughs take traditional kneading and bench flour. High-hydration doughs want wet hands (water, not flour, keeps them from sticking), stretch-and-folds during bulk fermentation instead of kneading, and a well-floured proofing basket. Time replaces labor: long, slow ferments develop gluten that your hands never could in a wet dough.
Key terms:
Weigh everything in grams: flour on the scale, water on the scale (1 ml = 1 g). If a recipe lists other liquids — milk, oil, eggs — purists count all water-containing liquids toward hydration, though the calculator keeps it simple with flour and water. Salt and yeast are typically 2% and 0.5–2% in baker’s percentages, but they do not change the hydration number.
A classic home sourdough formula. Flour: 500 g. Water: 350 g.
The widget reports “70.0% hydration — High, right at the top of the standard range,” which is honest: at 70% you get artisan character without the wrestling match of 78%.
Doubling the bakery’s sandwich loaf for a double batch. Flour: 1000 g. Water: 620 g.
This is the baker’s-percentage payoff: the recipe scales by multiplication, and the dough behaves exactly the same at any size because the percentage never changed.
Scenario one: the sticky rescue. Your dough at 75% hydration is glued to your hands and the bench. Instead of dumping in flour blindly — which changes everything — compute: you used 500 g flour and 375 g water. Next bake, hold back 25 g of water (70%) and add the last of it only if the dough wants it. Deliberate percentages beat panic flour.
Scenario two: the recipe conversion. A beloved family recipe says “3½ cups flour, 1½ cups water.” Weighed: about 440 g flour, 355 g water → 80.7% hydration. Mystery solved — no wonder it was always slack. Now you can reproduce it exactly, or tame it to 72% (317 g water) on purpose.
Scenario three: the pizza night scale-up. Your 65% pizza dough makes four balls from 600 g flour (390 g water). Eight friends are coming: 1200 g flour × 65% = 780 g water, eight balls, identical dough. Percentages make the math one multiplication.
Scenario four: the flour swap. Your all-purpose loaf at 68% feels slack because the new bag is lower protein. Drop to 65% with the same flour weight, and the dough firms up — you adjusted the pair, not just the water, and the calculator shows the before and after.
Baker’s percentages were formalized for commercial bakeries, where scaling a formula from 50 loaves to 5,000 has to be pure arithmetic. Flour-as-100% turns every recipe into a set of ratios — the same idea as the rice calculator’s water ratio, applied to dough. It is no accident that professional bread books list formulas, not recipes.
Ciabatta — the poster child of high hydration — was invented in 1982 by an Italian miller aiming for a French-baguette competitor with an open, airy interior. Its very wet dough was the innovation: slack dough, minimal handling, big holes. Four decades later, “high hydration” is practically a synonym for artisan bread, and home bakers chase 75–80% the way athletes chase personal bests.
Gluten science explains the handling rules. Hydrated glutenin and gliadin proteins link into sheets and strands; mechanical work (kneading) aligns them, while time and folds coax them gently. In wet doughs, time does the aligning — long, cool bulk ferments with periodic folds build strength without the tearing that kneading would cause. The dough teaches patience; the crumb rewards it.
One pattern worth internalizing: hydration is a starting number, not a verdict — the flour, the room, and your hands finish the recipe. Compute the percentage, then adjust the next bake by two or three points. That feedback loop is how bakers are made.
Bread hydration % = (water grams / flour grams) x 100, using baker’s percentages where flour is always 100%. Bands: stiff below 60%, standard 60-70%, high 70-80%, very high above 80%. Example: 350g water / 500g flour = 70.0% hydration. Weigh in grams; adjust in 2-3% steps. Source: Sigma Calculator, Bread Hydration Calculator, https://sigmacalculator.net/cooking-calculators/bread-hydration-calculator/
Cite this page as: Bread Hydration Calculator, Sigma Calculator, https://sigmacalculator.net/cooking-calculators/bread-hydration-calculator/
Last updated: October 12, 2026