Sourdough Starter Feeding Calculator
Feed your starter at the right ratio and time so it peaks when you need it. Use this calculator whether you know when you want to mix, or you know when you are feeding right now.
How to Use This Calculator
- Choose whether you know mix time or feeding time.
- Pick your feeding ratio.
- Use the recommended flour/water and peak window output.
[sc_faq source=”starter-faq.json” title=”Frequently Asked Questions”]
What Does a Starter Feeding Ratio Mean?
When you feed your sourdough starter, the ratio describes how much starter you keep versus how much fresh flour and water you add. A 1:1:1 ratio means equal parts starter, flour, and water by weight. A 1:2:2 means you’re diluting the starter more — giving it a larger amount of food relative to its size. The ratio directly controls how quickly your starter peaks and how acidic it becomes.
A 1:1:1 ratio peaks quickly (4–6 hours at 75°F) and produces a more sour starter. A 1:5:5 peaks more slowly but produces a milder, more active starter that holds its peak longer — better for baking. This calculator converts any ratio to real gram amounts for your jar size, so you’re not doing mental math in the kitchen.
How to Know If Your Starter Is Ready to Use
Your starter is ready when it has at least doubled in size, smells yeasty and slightly sour, and passes the float test — a small spoonful dropped into water should float rather than sink. These signals together indicate peak activity: the yeast is strong and the gluten network is intact.
Timing matters. If you regularly use a 1:1:1 ratio, your starter will peak faster than if you use 1:5:5. In winter kitchens (65°F or below), any ratio will take significantly longer than at 75–80°F. Use this calculator alongside your kitchen temperature to plan when to feed so your starter peaks right when you’re ready to mix dough.
Adjusting Ratios for Different Situations
For a same-day bake: use a 1:1:1 or 1:2:2 ratio and let it peak at room temperature for 4–8 hours. For an overnight bake: use a 1:5:5 or 1:10:10 ratio before bed and it will peak by morning. If your starter has been in the fridge for a week or more, give it one or two refreshment feeds before using it in bread.
If you’re consistently getting dense bread despite what looks like an active starter, the problem is often timing rather than ratio. The starter may have peaked and started declining before you mixed the dough. Use the float test as your confirmation, not the clock.