Sourdough calculator (baker’s percentages)

Every ingredient of a loaf from baker’s percentages — scaled to any size.
Start from
Flour
cups
Water
%
Starter
%
Salt
%
Flour
4 cups + 3 tbsp (500 g)
Water
1 ½ cups + 1 tbsp (360 g)
Active starter
⅓ cup + 2 tbsp (100 g)
Salt
1 ¾ tsp (10 g)
Your dough weighs

970 g

74.5% hydration, counting the starter
4 cups + 3 tbsp (500 g) of flour.

How it works

Bakers write a recipe as percentages of the flour: 100% flour, 72% water, 20% starter, 2% salt. That way one recipe works for any size of loaf.
Type how much flour you want to use (or pick a number of loaves) and every other amount follows.

Questions

What are baker’s percentages?

Every ingredient as a percentage of the flour, which is always 100%. The everyday country loaf is 72% water, 20% starter and 2% salt: for 500 g of flour that is 360 g water, 100 g starter and 10 g salt.

What is the 1-2-3 sourdough ratio?

1 part starter, 2 parts water and 3 parts flour (plus about 2% salt). Counting the flour and water in the starter, it makes a dough of about 71% hydration.

How much salt goes in sourdough?

About 2% of the flour: 10 g — 1 ¾ tsp of fine salt — for 500 g of flour.

Sources

Ingredient Weight Chart
King Arthur Baking
Checked September 30, 2026. The figures are the bakers’; the model and the words are ours. Watch the dough, not the clock.

More free tools

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