Sourdough Starter Ratio
Calculator
Results
- Flour to feed (g)
- 400
- Water to feed (g)
- 400
- Refreshed starter weight (g)
- 900
Cooking results
| Flour to feed (g) | 400 |
| Water to feed (g) | 400 |
| Refreshed starter weight (g) | 900 |
formula-map diagram
- Flour to feed (g)
- 400
- Water to feed (g)
- 400
- Refreshed starter weight (g)
- 900
Formula breakdown
Formula
1 : f : w — flour = starter × f, water = starter × w= 400
Note
Simplified model: results are standard culinary ratios and stated per-kilogram rates. Real ovens, flours, ingredients and food-safety requirements vary, so use a thermometer and your own judgement.
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See all →Frequently asked questions
What does a starter feeding ratio like 1:1:1 actually mean?+
The three numbers represent parts of starter, flour, and water by weight, in that order, so 1:1:1 means equal weights of each; a 1:5:5 ratio means five times as much fresh flour and water as the starter you're feeding, which changes both growth speed and flavor.
Why does a higher ratio (like 1:5:5) make the starter less sour?+
A larger proportion of fresh flour dilutes the existing acids and gives the yeast more new food relative to the bacteria that produce sour flavor compounds, generally resulting in a milder-tasting, faster-rising starter compared to a low-ratio feed like 1:1:1.
How do I use this ratio to figure out how much starter to keep back?+
Decide your total desired starter weight, then split it according to the ratio proportions: for a 1:1:1 ratio making 300g total, that's 100g starter, 100g flour, and 100g water, discarding any extra starter beyond the 100g you're keeping to feed.
Does the ratio need to change for different feeding schedules?+
Yes, a starter fed once daily typically uses a lower ratio (1:1:1 to 1:3:3) so it has enough food to survive until the next feeding, while a starter fed twice daily or kept at room temperature in warm conditions can use a higher ratio since it's fed again sooner.
Why would I want to calculate this instead of eyeballing it?+
Consistent ratios by weight (not volume) produce a more predictable starter, since flour and water measured by volume vary significantly by how they're scooped, while getting the ratio wrong repeatedly can leave a starter too diluted to rise reliably or too concentrated to have enough food.