Bread Dough Hydration Explained in Grams

Dough hydration is the weight of the water divided by the weight of the flour, written as a percent. So 350 g of water mixed into 500 g of flour is 70 percent hydration. That one number tells you a lot about how a dough will feel, how it will handle, and what kind of crumb you'll get.

How to calculate dough hydration

Weigh everything, then divide. Here's the whole process:

1. Add up the weight of all the flour in the recipe.
2. Add up the weight of all the liquid.
3. Divide the liquid by the flour and multiply by 100.

Sourdough adds one small twist. Your starter is part flour and part water, so it counts on both sides. A starter fed with equal weights of flour and water is half flour and half water, so 100 g of starter adds 50 g to each total. King Arthur Baking walks through a country sourdough with 425 g of total water and 550 g of total flour: 425 divided by 550 is about 0.77, or 77 percent.

What the numbers feel like in real loaves

King Arthur Baking describes doughs in the 55 to 65 percent range as firm or stiff, and doughs from 75 to 85 percent made with all purpose flour as slack or sticky. A few of their recipes show the spread:

• Their Easiest Loaf of Bread You'll Ever Bake sits at 63 percent.
• A basic white bread formula in their baker's percentage guide uses 66 percent.
• Their baguette and country sourdough examples land at 77 percent.
• Pain de Campagne is about 80 percent.
• Pan de Cristal goes all the way to 100 percent.

Higher hydration usually means a more open crumb and a dough that's harder to handle. Lower hydration gives you a tighter crumb and a dough that shapes neatly, which is why sandwich loaves and rolls tend to live in the 60s.

What counts as water, and what doesn't

In King Arthur Baking's approach, any pourable liquid counts as water: milk, juice, beer, tea, coffee. Butter and eggs are usually left out of the math, but they still bring moisture. Eggs are roughly 75 percent water and butter about 18 percent, so an enriched dough will feel softer than its hydration number suggests.

Flour type matters too. Whole grain flour is thirstier, so a 75 percent whole wheat dough feels much firmer than a 75 percent all purpose dough. If you swap in whole wheat, expect to add water, and use the feel of the dough as your guide.

Why cups turn hydration into guesswork

King Arthur Baking counts a cup of all purpose flour as 120 g and a cup of water as 227 g. But a cup of flour scooped straight from a packed bag can hold up to 160 g. Look at what that does to a simple recipe with 4 cups of flour and 1 1/2 cups of water:

• Flour at 120 g per cup: 340.5 g of water in 480 g of flour is about 71 percent.
• Flour at 160 g per cup: the same water in 640 g of flour is about 53 percent.

Same recipe, same cups, and you've gone from a soft dough to a stiff one. Weighing the flour and water is the only way to get the hydration the recipe writer intended.

The small ingredients deserve the same care. A 500 g batch at 2 percent salt needs 10 g of salt, and a heaped spoon can push that well over. A MeasureMate digital measuring spoon scoops and weighs in one step, reads in 0.1 g steps, and has a tare button that zeroes the reading, so the salt and yeast land on target while your big scale handles the flour and water.

Quick questions

What hydration should a beginner start with?

Something in the low to mid 60s is friendly. King Arthur Baking's easiest loaf is 63 percent, which is firm enough to knead and shape without much sticking.

Does sourdough starter count toward hydration?

Yes. Split the starter into its flour and water and add each to the totals. A starter kept at equal weights is half and half.

Is milk counted as water?

For the hydration math, yes. Just know that milk has fat and other solids, so a milk dough feels a bit firmer than a water dough at the same percent.

Weights based on King Arthur Baking's bread hydration guide, baker's percentage reference and ingredient weight chart.