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Sourdough Hydration Calculator

Enter flour, water, starter weight, and starter hydration to calculate total flour, total water, starter contribution, and true sourdough hydration.

Leave starter hydration at 100% for equal flour and water.

Enter flour and water.

Add starter when the dough includes one. Its flour and water will be counted.

How to Use the Sourdough Hydration Calculator

Enter the flour and water added directly to the dough.

Enter the total weight of starter or levain used. Leave this field blank when the dough contains no starter.

Keep starter hydration at 100% for a starter containing equal flour and water by weight. Enter another percentage for a stiff or liquid starter.

The calculator shows total dough hydration and separates the flour and water contributed by the starter.

How Dough Hydration Is Calculated

Dough hydration is total water divided by total flour, multiplied by 100.

A dough containing 350 grams of water and 500 grams of flour has 70% hydration.

In baker's percentage, flour is the 100% reference and the other ingredients are measured against total flour weight.

Hydration examples using 500 grams of flour

Hydration examples using 500 grams of flour
HydrationTotal flourTotal water
60%500 g300 g
65%500 g325 g
70%500 g350 g
75%500 g375 g
80%500 g400 g

Swipe horizontally to view the full table.

Why Starter Must Be Included

Sourdough starter contributes both flour and water to the final dough.

A 100-gram starter at 100% hydration contains 50 grams of flour and 50 grams of water.

Ignoring those amounts produces a hydration percentage that does not represent the complete dough formula.

What Starter Hydration Means

Starter hydration expresses starter water as a percentage of starter flour.

A 100% hydration starter contains equal flour and water by weight.

A 60% starter contains 60 grams of water for every 100 grams of flour. A 125% starter contains 125 grams of water for every 100 grams of flour.

Starter flour and water examples

Starter flour and water examples
Starter hydrationFlourWaterTotal starter
50%100 g50 g150 g
60%100 g60 g160 g
100%50 g50 g100 g
125%100 g125 g225 g

Swipe horizontally to view the full table.

How to Interpret the Result

Higher hydration means more water relative to flour. It does not automatically mean a better loaf.

Flour absorption, protein, whole-grain content, fermentation, temperature, mixing, folding, shaping, and baking all affect dough behaviour.

Use hydration to compare formulas and record adjustments rather than as a complete prediction of the finished bread.

What the Calculator Includes

Total flour includes flour entered directly and flour inside the starter.

Total water includes water entered directly and water inside the starter.

Starter flour and starter water are displayed separately so the calculation can be checked.

What the Calculator Does Not Include

The tool does not estimate water contributed by eggs, milk, butter, fruit, vegetables, soaked grains, or other ingredients.

It does not calculate salt percentage, inoculation, prefermented flour percentage, total dough weight, fermentation time, proofing time, or desired dough temperature.

Use a complete bread-formula calculator when those values are needed.

Privacy and Local Processing

The calculation runs entirely in the browser.

Ingredient amounts are not uploaded, added to the page URL, or permanently stored.

Sourdough Hydration Formulas

The starter is separated into flour and water before the final dough hydration is calculated.

Formula variables

Total starter weight
Starter hydration percentage
Flour inside the starter
Water inside the starter
Flour added directly to the dough
Water added directly to the dough
Total flour
Total water
Final dough hydration percentage
Starter flour
Starter water
Total flour
Total water
Dough hydration

Examples

Dough with a 100% hydration starter

1

Input

500 g flour, 350 g water, and 100 g starter at 100% hydration.

Show result

Result

550 g total flour, 400 g total water, and 72.73% hydration.

Starter contribution

2

Input

100 g starter at 100% hydration.

Show result

Result

50 g starter flour and 50 g starter water.

Dough without starter

3

Input

500 g flour, 350 g water, and no starter.

Show result

Result

70% hydration.

Stiff starter

4

Input

160 g starter at 60% hydration.

Show result

Result

100 g starter flour and 60 g starter water.

Liquid starter

5

Input

225 g starter at 125% hydration.

Show result

Result

100 g starter flour and 125 g starter water.

Frequently Asked Questions

How do I calculate sourdough hydration?

Divide total water by total flour and multiply by 100. Include the water and flour inside the starter.

Does starter count toward dough hydration?

Yes. Starter flour and starter water are part of the final dough.

What does 100% hydration starter mean?

It means the starter contains equal weights of flour and water.

How much flour and water are in 100 grams of starter?

At 100% hydration, 100 grams of starter contains 50 grams of flour and 50 grams of water.

Can I use a stiff starter?

Yes. Enter its actual hydration percentage. A stiff starter contains less water relative to flour.

Can starter hydration exceed 100%?

Yes. A starter above 100% hydration contains more water than flour by weight.

Can I calculate dough with no starter?

Yes. Leave the starter amount blank or enter zero.

What is a good sourdough hydration?

There is no universal best percentage. The flour, bread style, fermentation, and handling method all matter.

Does higher hydration guarantee an open crumb?

No. Flour strength, fermentation, shaping, gas retention, and baking also affect crumb structure.

Does this include water from milk or eggs?

No. It includes plain water and the water inside the starter only.

Does hydration predict fermentation time?

No. Fermentation also depends on starter strength, inoculation, dough temperature, flour, salt, and room conditions.

Are my ingredient amounts uploaded?

No. The calculation runs locally in the browser.