
Every once in a while, I’ll look at the list of search terms that brings people to my blog. As you can see from some of the search terms above, lots of people look for sourdough starter equivalents.
Most of the sourdough bread recipes I’ve seen (and have written) call for starter weighed in grams. If you don’t have a scale, you’ll want those measurements in volume. But I’ve included conversions going in the other direction as well, from US cups to grams. Sometimes you’ll use a recipe that lists an ingredient in cups but you’d rather use your scale—especially if you live outside the US.

I worked out these conversions using my 100 percent hydration sourdough starter, which contains equal parts flour and water by weight. When I feed my sourdough starter (which I generally keep small), I’ll add 40 grams of flour and 40 grams of water to a spoonful of starter from the previous batch.
Metric to US
Metric | US |
---|---|
25 grams sourdough starter | 1 tablespoon + 1 generous teaspoon |
50 grams sourdough starter | 3 tablespoons |
100 grams sourdough starter | 1/3 cup + 1/2 tablespoon |
150 grams sourdough starter | 1/2 cup + 1 tablespoon |
320 grams sourdough starter | 1 cup + 2 1/2 tablespoons |
US to Metric
Metric | US |
---|---|
1 tablespoon sourdough starter | 17 grams |
2 tablespoons sourdough starter | 34 grams |
1/4 cup sourdough starter | 69 grams |
1/3 cup sourdough starter | 92 grams |
1/2 cup sourdough starter | 138 grams |
2/3 cup sourdough starter | 184 grams |
1 cup sourdough starter | 276 grams |
Go here for a post that converts the sourdough bread ingredients to US cups.

Thank you. This is so helpful. I’m in the US and only use weights. I’m glad I found your blog using those keywords.
Hi Dorothy,
I’m glad you found it helpful. Apparently a lot of people are looking for this info!
Happy baking,
Anne Marie
Help! How many cups is in 475 grams of starter, thank you.
Hi Tommy,
That’s about 1 3/4 cups.
~ Anne-Marie
HI, if 120 g of Sourdough discard? I checked and it is 1/2 cup flour with 1/4 water. However, for how long we need to leave it to ferment before using in a cookie recipe? (We do not want to make the bread; but using the discard in a different recipe). Thank you very much, Zainab,
Hello! If you use active starter, you’d wait until it has approximately doubled its size. This can take six hours or longer after a feeding, depending on your kitchen’s temperature (or it might ferment faster). You can use the discard (the starter you remove before feedings) any time. I hope that helps!