Sourdough Feeding Calculator
Enter the amount you want and a feeding ratio to get the grams of starter, flour and water to mix.
Reading a feeding ratio
A ratio of 1:5:5 means 1 part starter, 5 parts flour and 5 parts water by weight. For a 220 g total that is 20 g starter, 100 g flour and 100 g water. A larger feed ratio slows the rise and lengthens the time to peak.
Equal flour and water parts keep a 100% hydration feed. Using more flour than water, such as 1:2:1, makes a stiffer 50% feed.
Keeping the amount small
Discarding and feeding a small base, for example 10–20 g of starter, saves flour. Enter the total you need for the next bake and the calculator works out the rest.
FAQ
Which ratio should I use?
1:1:1 peaks fast and suits warm kitchens and daily feeding. 1:5:5 or higher slows things down for overnight or fridge-friendly schedules. Your own timing and temperature decide.
Does the feed hydration equal the starter hydration?
Only if the starter you keep was also at that hydration. The feed percentage counts the fresh flour and water only, not the water already inside the old starter.
Can I use whole grain flour?
Yes. Whole grain flour ferments faster and absorbs more water, so you may add a little extra water.
Other Languages
References
How we make sure
We check this tool with the automated test suites linked below. Example checks are shown in their original language.
- Verification method
- Check that 1:5:5 for 220 g gives 20/100/100 g and that 1:2:1 gives a 50% feed with parts summing to the total.
- Comparison reference
- Hand arithmetic on the ratio parts described in King Arthur’s feeding-ratio article.
- Verification scope
- Only these samples and boundaries are checked; this does not prove correctness for every input or guarantee a bake.
Test source and cases (select a file to read it)
-
baker-tools.test.js
- sourdough feeding: 1:5:5 for 220 g is 20 g starter, 100 g flour and 100 g water
- sourdough feeding: 1:2:1 gives a 50% hydration feed and parts sum to the total
These checks cover the listed examples and boundaries, not every possible input. Round trips and checks using the same library are not independent verification.