Dough Hydration Calculator

Using the calculator

The calculator has two modes, matching the two questions bakers actually ask mid-recipe.

Find hydration %: you already know your amounts and want the number. Enter flour and water in grams and read the percentage. This is the mode for checking a recipe you found, or working out what you just poured into the bowl.

Find water needed: you know the hydration you want and need the water weight. Enter your flour and a target percentage; the result is the water to add on the scale. With the starter option on, the water the starter carries is already subtracted for you.

Results update as you type. There is nothing to submit. Click Share result to copy a link that pre-fills your numbers.

True vs apparent hydration

Sourdough starter is not just an ingredient. It is flour and water in disguise. A 100% hydration starter, which is what you have if you feed equal weights of flour and water, is half flour and half water. 100g of starter brings 50g of flour and 50g of water to the dough.

That gives every sourdough recipe two hydration numbers. The apparent hydration is added water divided by added flour, ignoring the starter. The true hydration counts the starter's flour and water in both totals. Most recipes and most online calculators quote the apparent number, which is why a “75% dough” can feel wetter than expected: its true hydration is often 2 to 3 points higher.

This calculator shows both. The gap widens as you use more starter, and it flips direction with a stiff starter (below 100% hydration), which brings proportionally more flour than water. If your starter is fed 1:1:1 by weight it is 100%; if you feed by volume, one cup of flour to half a cup of water lands roughly at 60–65%.

Hydration ranges by bread type

The percentage is a prediction of how the dough behaves in your hands. These ranges are where each style typically lives. Treat them as starting points; flour choice moves the feel by several points in either direction.

Whole-grain flours absorb 5–10% more water than white flour at the same percentage, so a 75% whole wheat dough handles like a white dough in the high 60s. Enriched doughs read low but feel wetter than their number, because butter and eggs act as liquid too.

Worked example

Say your bowl has 500g of flour, 340g of water, and 100g of 100% hydration starter. Here is the full calculation, step by step.

1. Split the starter. At 100% hydration it is equal parts by weight: 100g starter = 50g flour + 50g water.
2. Total the flour: 500 + 50 = 550g.
3. Total the water: 340 + 50 = 390g.
4. Divide: 390 ÷ 550 × 100 = 70.9% true hydration.

Ignore the starter and you would call this dough 340 ÷ 500 = 68%. The 2.9-point gap is exactly why doughs from starter-blind recipes feel wetter than advertised. Enter the same numbers in the calculator above with the starter option on and you will see both figures.

Going the other way: same 500g of flour and 100g of starter, but now you want 72% hydration. Total flour is 550g, so total water must be 550 × 0.72 = 396g. The starter contributes 50g, leaving 396 − 50 = 346g of water to add. That is what the water mode reports.

Frequently asked questions

How do you calculate dough hydration?

Divide the total water weight by the total flour weight and multiply by 100. A dough with 500g of flour and 340g of water is 340 ÷ 500 × 100 = 68% hydration. If the dough contains sourdough starter, add the flour and water inside the starter to both totals before dividing. That is the number this calculator reports.

What does 75% hydration mean?

It means 75 grams of water for every 100 grams of flour. For a loaf with 500g of flour, that is 375g of water. In handling terms, 75% sits in the high range typical of artisan sourdough: a slack, slightly sticky dough that rewards good technique with an open, irregular crumb.

Does sourdough starter count toward hydration?

Yes. Starter is itself flour and water. A 100% hydration starter is half flour, half water by weight, so 100g of starter adds 50g of flour and 50g of water to your dough. Recipes that ignore this overstate or understate the real hydration, and the error grows with the amount of starter. This calculator counts the starter in both totals.

How much water do I need for 500g of flour?

Multiply the flour weight by your target hydration. For 500g of flour: 325g of water gives 65%, 350g gives 70%, and 375g gives 75%. If you use sourdough starter, subtract the water the starter already brings; the calculator's water mode does that arithmetic for you.

What is a good hydration for beginners?

65–70% is the sweet spot for a first lean loaf. The dough is workable, holds its shape during shaping, and still produces a reasonably open crumb. Sandwich and pan loaves are even more forgiving at 55–65%. Save 75% and above for when stretch-and-folds feel routine.

What hydration should pizza dough be?

It depends on the style. Neapolitan runs 55–62%, New York 63–67%, Detroit 70–75%, and Roman al taglio 75–80%. Home ovens generally favour the middle of each range; very high hydration needs the fast bake of a very hot oven to set properly.

Is higher hydration always better?

No. More water opens the crumb and thins the crust, but it also makes the dough slack, sticky, and less forgiving to shape. Bagels need a stiff 55–60% dough to survive boiling; a focaccia wants 80% or more. Match the hydration to the bread you are making and to your comfort handling wet dough.

Sources

1. King Arthur Baking Company. Hydration in bread dough, explained. kingarthurbaking.com Defines hydration as total water over total flour, including the contents of a preferment or starter.
2. The Perfect Loaf. What Is Dough Hydration? (And How to Get It Right). theperfectloaf.com
3. Hamelman, J. Bread: A Baker's Book of Techniques and Recipes. 2nd ed. John Wiley & Sons, 2012. Hydration practice for lean and sourdough breads.
4. Reinhart, P. The Bread Baker's Apprentice. Ten Speed Press, 2001. Dough-stiffness classification from stiff bagel doughs to rustic ciabatta.

The formula, its edge cases, and every range on this page are documented on the methodology page.