Sourdough Starter Calculator

Want to know exactly how much flour and water to feed your sourdough starter? This sourdough starter calculator does the math for you using baker’s percentages. Just enter how much starter you’re working with and your preferred feeding ratio (e.g., 1:1:1 or 1:2:2), and it’ll give you the amounts you need for consistent results every time.

👉 Need a full guide to starting and maintaining a sourdough starter? Read my complete sourdough starter guide here.

Sourdough Starter Calculator

Need to build a levain for your bake? Just enter the amount you need and your preferred feeding ratio.

Total levain needed (g):
Feeding ratio:

How I Store My Starter:
When I bake, I take my starter from the fridge, use it to build the levain, and also scoop out about 20g to feed and return to the fridge for next time (usually at 1:1:1 or 1:2:2). Don’t worry if you don’t get 20g. Even a tiny scrap of starter can be fed and grown again.

🕒 General rise times:
- 1:1:1 = ~4–6 hours
- 1:2:2 = ~6–8 hours
- 1:3:3 = ~8–10 hours
- 1:5:5 = ~10–12 hours
These assume a 100% hydration levain. Stiffer levains (<70% hydration) will take longer.

Note on very stiff starters:

If you’re working with something like a pasta madre (often around 45–50% hydration), expect a much slower rise.

Pasta madre is a traditional Italian stiff starter typically kept at 45–50% hydration and often maintained in a cloth wrap. Because of its low moisture and tight structure, fermentation is much slower. These starters are used in enriched doughs like panettone and follow a different feeding and maintenance schedule.