Free sourdough calculators

Feed your starter on schedule, not on guesswork.

Pick a ratio, set your kitchen temperature, and get exact grams plus a realistic window for when your starter will peak.

Use the calculatorHow often to feed?
  • No sign-up
  • Grams, °F or °C
  • Works on your phone

Feeding calculator

Feeding ratio (starter : flour : water)
Starter50 g
Flour100 g
Water100 g
Estimated peak6–9 hrs

Total 250 g. Times vary with flour, starter strength and jar size, so watch for a domed, bubbly top that has roughly doubled.

More sourdough calculators

Rise time by temperature

Estimate bulk fermentation for your kitchen, warm or cold.

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Hydration

True dough hydration, counting the flour and water in your starter.

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Recipe scaler

Scale any loaf by baker's percentages to the weight you want.

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Starter guides

How often should you feed a sourdough starter?

Counter vs fridge schedules, and how to tell when it's hungry.

Sourdough starter not rising? 8 fixes

Temperature, flour, ratio and the hooch stage, in order of likelihood.

Feeding ratios explained

What 1:1:1 vs 1:5:5 actually changes, and which to pick.

Coming soon

Printable feeding schedules

Fridge-friendly weekly schedules, a 7-day new-starter calendar and a starter log.

See the printables