Calculator
Enter the total weight of each ingredient. The starter is included in the dough calculation, with its own hydration level.
What is baker's percentage?
Baker's percentage (also called baker's math) expresses every ingredient as a percentage of the total flour weight. The flour is always 100%. So a dough with 500g flour and 375g water has 75% hydration. This system makes it easy to scale recipes up or down, and to compare formulas regardless of batch size.
Hydration levels reference
| Hydration | Dough feel | Best for |
|---|---|---|
| 50-60% | Firm, easy to handle | Bagels, pretzels, pizza |
| 60-68% | Tacky, manageable | Sandwich bread, rolls |
| 68-75% | Soft, slightly sticky | Boules, batards, everyday sourdough |
| 75-82% | Sticky, needs technique | Ciabatta, focaccia, open crumb |
| 82-100% | Wet, hard to shape | Pan breads, high-hydration experiments |
The formulas
- Hydration %: (Water ÷ Flour) × 100
- Starter %: (Starter ÷ Flour) × 100
- Salt %: (Salt ÷ Flour) × 100
- Total dough weight: Flour + Water + Starter + Salt
- Effective hydration: (Water + Starter water) ÷ (Flour + Starter flour) × 100
How to use this calculator
- Choose a mode: Hydration (check an existing recipe), Scale (start from a target flour amount), or Starter Build (plan a levain).
- Enter your values. The calculator updates instantly.
- For hydration mode, enter total ingredient weights including your starter.
- For scaling mode, enter your target flour and desired hydration — the calculator returns exact weights.
- Click "Copy shareable link" to save or share your formula.
Frequently asked questions
What hydration should I start with?
If you are new to sourdough, start at 68-72%. This range produces a manageable dough that is still open enough to develop good crumb. Once you are comfortable with shaping, gradually increase toward 75-80% for a more open crumb.
Should I count the starter in the hydration calculation?
Yes, for accuracy. A 100% hydration starter is half flour and half water, so it contributes both. This calculator automatically subtracts the starter's flour and water from your main ingredients to give you the true effective hydration.
What is the ideal salt percentage?
Most sourdough recipes use 1.8% to 2.2% salt relative to flour weight. Below 1.5% tastes flat; above 2.5% starts to inhibit fermentation. 2% is a good default.
How much starter should I use?
Typical sourdough recipes use 10-25% starter (relative to flour weight). Lower percentages (10-15%) produce a slower, more flavorful ferment. Higher percentages (20-25%) speed things up but can taste more sour and less complex.
How do I scale a recipe from 500g to 1000g flour?
Simply double every ingredient. Baker's percentage makes this trivial: if your original recipe uses 75% hydration and 2% salt, both stay the same — only the flour weight changes, and every other ingredient scales proportionally. Use the Scale mode above to do this automatically.