Sourdough Hydration Calculator
Calculate total dough hydration including your starter, with separate flour and water contributions for liquid or stiff starter.
72.7% total dough hydration
- Added-water hydration
- 70%
- Flour in starter
- 50 g
- Water in starter
- 50 g
- Total flour
- 550 g
- Total water
- 400 g
(400 g water ÷ 550 g flour) × 100 = 72.7%.
Count only starter mixed into the dough, excluding your reserve. This calculator counts flour and water only; eggs, milk, fruit and other ingredients need their own recipe-specific accounting.
The calculation
Starter flour = starter weight ÷ (1 + starter hydration ÷ 100). Starter water = starter weight − starter flour. Total hydration = total water ÷ total flour × 100.
Worked example
With 500 g added flour, 350 g added water and 100 g of 100%-hydration starter, the starter contributes 50 g flour and 50 g water. Total hydration is 400 ÷ 550 × 100 = 72.7%, while added-water hydration is 70%.
What to check
The starter amount is the portion that goes into the dough. Exclude your reserve. Hydration compares flour and water by weight; flour type and other ingredients still change handling. This calculator does not account for water in milk, eggs, fruit or other additions.
Read the method
By Crispy Crust · Published 10 November 2026 · How we write and review guides