Calculate ingredient amounts for sourdough bread using baker's percentages. Enter your total flour weight and desired hydration, and get exact amounts for flour, water, salt, and starter.
Sourdough bakers don't write recipes in cups. They write them in baker's percentages — where flour is always 100% and every other ingredient is expressed as a percentage of the flour weight. A classic country sourdough is 100% flour, 75% water (75% hydration), 20% starter, 2% salt. That recipe scales perfectly: 500 g of flour means 375 g of water, 100 g of starter, and 10 g of salt. A 2 kg batch is 2000 g flour, 1500 g water, 400 g starter, 40 g salt. Same dough, same flavor, any size.
This calculator gives you the math. Enter your target flour weight and the percentages, and it returns gram-accurate amounts for every ingredient — including the often-overlooked correction for starter hydration (a 100% hydration starter is half flour, half water, so 100 g of starter actually contributes 50 g of flour and 50 g of water to your dough, slightly changing the final hydration).
Sourdough is the technique where weight-vs-volume matters most. A "cup" of bread flour can be 110–160 g depending on how it's measured; that 50 g swing on a 500 g recipe is the difference between 75% and 85% hydration — the difference between a manageable dough and a wet, sticky mess. Buy a kitchen scale. This calculator gives you the recipe; the scale lets you actually follow it.
**Scenario:** Beginner sourdough: 500 g bread flour, 75% hydration, 20% starter, 2% salt. **Calculation:** Flour 500 g. Water 500 × 0.75 = 375 g. Starter 500 × 0.20 = 100 g. Salt 500 × 0.02 = 10 g. True hydration accounting for 100% starter: total flour 550 g, total water 425 g → 77.3%. **Result:** Mix flour + 350 g water (hold back 25 g for the salt addition). Autolyse 1 hour. Add starter, mix, rest 20 min. Add 10 g salt + 25 g held-back water, mix in. 4 stretch-and-folds at 30-min intervals. Bulk ferment until 50% rise (~4–5 hours total at 70°F). Pre-shape, rest, final shape, cold proof 12 hr overnight. Bake in Dutch oven: 500°F covered 20 min, 450°F uncovered 25 min.
**Scenario:** Targeting big open holes: 1 kg bread flour, 82% hydration, 15% starter, 2% salt. **Calculation:** Water 820 g, starter 150 g (75 g flour + 75 g water), salt 20 g. True hydration: total flour 1075 g, total water 895 g = 83.3%. **Result:** Demanding dough — sticky and slack. Requires gentle handling (no kneading; coil folds instead). 4–5 coil folds during 5–6 hour bulk. Cold retard 18 hours. Bake on stone or steel with steam injection or use a deep Dutch oven. The 80%+ hydration gives the open, airy crumb that sourdough Instagram is built around — but expect failure on early attempts.
**Scenario:** Want enriched, soft sourdough for daily use: 500 g bread flour, 68% hydration, 15% starter, 1.8% salt, plus 5% honey and 5% olive oil. **Calculation:** Water 340 g, starter 75 g, salt 9 g, honey 25 g, oil 25 g. Lower hydration produces tighter crumb perfect for sandwiches. Honey adds sweetness and helps with browning; oil adds tenderness. **Result:** Tighter, sandwich-friendly crumb at 68% hydration. Shape into a loaf pan rather than free-form boule. Bake at 425°F for 35–40 min covered with foil for first 25 min. The enriched dough is more forgiving than the lean high-hydration version — good "everyday bread" project.
**Use baker's percentages whenever:**
- **Scaling a recipe**: a 500 g recipe scaling to 2 kg requires only multiplying by 4. Same percentages, different absolute amounts. - **Adjusting hydration**: tried 70%, want to push to 75% next time. Calculate the water increase directly. - **Sharing a recipe with another baker**: percentages travel between countries, languages, and units cleanly. - **Substituting flour types**: swapping 20% whole wheat for the same percentage of bread flour requires no other changes (initially — though whole wheat absorbs more water, so you may need to bump hydration). - **Comparing recipes**: two recipes that both say "1 cup water" are uncomprable; "75% hydration" tells you the dough character immediately. - **Diagnosing problems**: too sour? Try lower starter %, longer cold proof. Too dense? Try higher hydration, longer bulk, more starter, or fresher starter.
**The standard sourdough variables and what each controls:**
- **Hydration**: open vs tight crumb, crust crispness, ease of handling. - **Starter %**: fermentation speed (more starter = faster), sourness profile (less starter, slower ferment = more complex flavor). - **Salt %**: flavor, yeast inhibition. Below 1.5% the dough over-ferments; above 2.2% it gets sharp. - **Bulk time**: gluten development, dough volume increase, flavor development. - **Cold proof time**: complex flavor development, surface tension for scoring. - **Bake temp + time**: crust color, oven spring, doneness.
**Common starter setups:**
- **100% hydration**: most common — easy to feed (1:1:1 ratio by weight), runs faster, slightly milder flavor. - **50–60% hydration (stiff levain)**: slower, more complex flavor, traditional in French bakeries. - **Rye starter**: more sour, very active, useful for boosting flavor.
**When to switch from percentages back to "recipe" thinking:**
Almost never. Once you understand percentages, recipes feel restrictive. Most pro bakers think entirely in percentages and recalculate amounts based on the day's flour weight, requested loaf count, and target hydration.
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Water as % of flour (65-80% typical)
Starter as % of flour (15-25% typical)
Salt as % of flour (1.8-2.2% typical)
100% = equal parts flour and water in starter
Total Dough Weight
885g
Effective Hydration
75.0%
Starter Amount
100g
| Ingredient | Amount (g) |
|---|---|
| Flour (add to bowl) | 450g |
| Water (add to bowl) | 325g |
| Starter | 100g |
| Salt | 10.0g |
| --- | --- |
| Total Flour (incl starter) | 500g |
| Total Water (incl starter) | 375g |
| Total Dough | 885g |