Sourdough starter feeding calculator

Enter the weight you want immediately after feeding. Choose a listed ratio or enter your own parts in the order seed starter, flour, water.

Custom parts must all be greater than zero. The target is the mixed weight before fermentation, not an amount to add to the seed starter.

Enter your values, then calculate.

Method and limitations

Ratios describe weights, not volumes. For target weight M and parts a:b:c (seed starter:flour:water), each portion is M × its parts / (a + b + c). The target includes the seed starter. The listed ratios are calculation options, not feeding recommendations. No maturity time or final hydration is inferred; the seed starter already contains flour and water. Fermentation and handling losses are excluded.

Sources

No external reference is documented for this calculation; its method and limitations are described above.