You can use this tool to calculate the ingredient amounts for baking bread. If you’re not familiar with some of the terms, refer to the glossary section

Ingredients
Levain g at % Hydration
Flour g
Water g
Yield
Total Flour
Total Water
Bread g at % Hydration

Glossary

Autolyze
Process of mixing water and flour before adding the levain or salt.
Baker’s Percentage
A method of representing ingredient amounts as a percentage of the total amount of flour in a mixture.
See the following table for an example:
Ingredient Actual Amount Real Percentage Baker’s Percentage
White Flour 100g 32.9% 50%
Whole Wheat Flour 100g 32.9% 50%
Water 100g 32.9% 50%
Salt 4g 1.3% 2%
Hydration
The ratio of flour to water in a mixture, in baker’s percentages.
Levain
A sourdough starter that’s been recently fed and matured. Levain is typically added to the flour and water mixture when it reaches its peak rise.
Starter
Also called a sourdough starter, a mixture of flour and water that has developed yeast and become acidic, gaining a sour smell and taste.