Quick Answer
A sourdough hydration calculator finds the true water-to-flour ratio in your dough by decomposing the starter into its flour and water components: hydration % = (total water / total flour) × 100. For a 100% hydration starter, half its weight is flour and half is water — ignoring this makes your actual hydration higher than the recipe suggests.
Sourdough Hydration Formula
This sourdough hydration calculator uses baker’s math to split your starter into its flour and water components, then adds those to the recipe totals. The result is the true hydration — the number that actually controls your dough’s feel and crumb.
Starter water = Starter weight − Starter flour
True hydration = (Recipe water + Starter water) / (Recipe flour + Starter flour) × 100
Example: 500 g flour, 350 g water, 100 g starter at 100% → total flour 550 g, total water 400 g → 72.7% hydration.
| Hydration range | Level | Crumb texture | Best for |
|---|---|---|---|
| 50–64% | Low | Tight, dense | Bagels, pretzels, stiff doughs |
| 65–69% | Beginner | Even, soft | First-time sourdough bakers |
| 70–74% | Standard | Balanced, medium-open | Daily artisan loaves |
| 75–79% | High | Open, irregular holes | Experienced bakers |
| 80%+ | Very high | Extreme open, custard-like | Ciabatta, focaccia |
How to Use the Sourdough Hydration Calculator
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Enter your recipe flour and water
Type the flour weight and water weight from your recipe in grams (or tap “Ounces” to switch). These are the amounts you add directly to the bowl — not including what’s inside the starter.
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Enter your starter amount and hydration
Type how much mature sourdough starter (levain) you add. Then type its hydration — 100% means equal parts flour and water (most common). The calculator splits it automatically.
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Read your true hydration
The result card shows the true dough hydration %, a level badge (Beginner / Standard / High), a color-coded gauge and a one-line crumb texture guide. Below that: total flour, total water, total dough weight, salt, and a full baker’s percentage breakdown.
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Scale your recipe (optional)
Open Advanced options, type a target total dough weight and tap Scale recipe. All ingredients scale proportionally while keeping the same hydration, starter ratio and salt percentage.
Sourdough Hydration Examples
| Recipe | Flour | Water | Starter (hydration) | True Hydration | Level |
|---|---|---|---|---|---|
| Beginner country loaf | 500 g | 325 g | 100 g (100%) | 68.2% | Beginner |
| Standard artisan boule | 500 g | 350 g | 100 g (100%) | 72.7% | Standard |
| High-hydration batard | 500 g | 400 g | 100 g (100%) | 81.8% | Very high |
| Stiff-starter focaccia | 400 g | 340 g | 80 g (60%) | 83.1% | Very high |
