Sourdough Starter Feeding Calculator

What this tool does

A ratio of 1:5:5 means one part old starter to five each of flour and water, which is a generous feed that takes eight to twelve hours at room temperature. Feed less generously, say 1:1:1, and it will be ready in three or four hours but sour faster. The last result works backwards: how much to keep if you know how much starter the recipe needs.

Formula

feeding in the ratio starter : flour : water

Variables

Worked example

Limitations

• The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
• The default values are typical reference figures, not measurements of your situation. Replace them with your own data whenever you have it.