Fresh Milled Sourdough Starter Calculator
Calculate your starter ratio and hydration, build a starter by hydration, or build a starter by ratio.
What ratio and hydration is my starter?
Enter your starter, flour, and water weights to calculate the feeding ratio and final hydration percentage.
Starter Feed
Optional Starter Details
Leave the starter hydration blank and the calculator will assume your existing starter is 100% hydration.
I want a starter with a specific hydration
Enter your starter amount, desired hydration, and total flour to add. The tool will calculate the water needed and show your final starter.
Build by Hydration
Optional Starter Details
This calculates the water needed so the final starter mixture reaches your target hydration.
I want a specific starter ratio
Enter your starter amount and desired starter:flour:water ratio. The tool will calculate the flour, water, and final hydration percentage.
Build by Ratio
Optional Starter Details
The flour and water amounts are based on your desired ratio and existing starter weight.
Quick Guide
- 1:1:1 = equal parts starter, flour, and water by weight
- 1:2:2 = a larger feed that can help slow acidity and build strength
- 100% hydration = equal flour and water by weight
- Stiffer starter = lower hydration
- Looser starter = higher hydration
Fresh milled flour can ferment differently than commercial flour, so timing, rise, and texture may vary even when the ratio is the same.
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Disclaimer
This calculator provides estimates based on ingredient weights and assumed starter hydration. Results may vary depending on flour type, milling method, temperature, and fermentation conditions. Always use your judgment and adjust based on how your starter looks and behaves.