# Sourdough Calculator

Calculate sourdough bread ingredient amounts from flour weight, hydration, starter percentage, and salt. Accounts for flour and water in the starter.

## What this calculates

Sourdough baking is all about ratios. This calculator takes your desired flour weight and hydration level and works out exactly how much water, starter, and salt you need. It accounts for the flour and water already in your starter so your final dough hydration is accurate.

## Inputs

- **Total Flour Weight** (g) — min 50, max 10000 — Total flour weight for the final dough (not including flour in the starter).
- **Hydration** (%) — min 50, max 120 — Water as a percentage of flour. 70-75% is standard, 80%+ is high hydration.
- **Starter Percentage** (%) — min 5, max 50 — Starter as a percentage of flour. 15-25% is typical.
- **Starter Hydration** (%) — min 50, max 200 — Hydration of your starter. 100% means equal parts flour and water by weight.
- **Salt Percentage** (%) — min 0, max 5 — Salt as a percentage of flour. 1.8-2.2% is standard.

## Outputs

- **Flour (in the mix)** — Flour to add to the dough (excluding flour in the starter)
- **Water (in the mix)** — Water to add to the dough (excluding water in the starter)
- **Starter** — Weight of sourdough starter to use
- **Salt** — Salt to add
- **Total Dough Weight** — Approximate weight of the final dough before baking

## Details

Baker's percentages express every ingredient as a percentage of the total flour weight. If you use 500 g of flour at 75% hydration, you need 375 g of total water. At 20% starter, you need 100 g of starter. But here is the catch: your starter already contains flour and water. A 100% hydration starter is half flour and half water by weight, so 100 g of starter adds 50 g of flour and 50 g of water to your dough.

This calculator subtracts the flour and water in the starter from the totals, so the amounts you see for "flour" and "water" are what you actually add to the mixing bowl alongside the starter. That way your true dough hydration matches your target.

Starter percentage controls fermentation speed. More starter (25-30%) means a faster rise, which is handy in cold kitchens. Less starter (10-15%) gives a slower, more flavorful ferment. Most recipes land around 20%. Salt is typically 1.8 to 2.2% of flour. It controls fermentation, strengthens gluten, and adds flavor. Going below 1.5% makes fermentation harder to control; going above 2.5% can taste noticeably salty.

## Frequently Asked Questions

**Q: What hydration should I use?**

A: For beginners, 70 to 75% hydration is a good starting point. It produces a manageable dough that is not too sticky. Higher hydration (78 to 85%) gives a more open crumb with larger holes but is harder to shape. Very high hydration (85%+) is for experienced bakers and typically used in ciabatta-style breads.

**Q: Why does starter hydration matter?**

A: Because your starter contains both flour and water, its hydration level changes how much of each it contributes to the dough. A 100% hydration starter is 50/50 flour and water. A 75% hydration starter has more flour than water. The calculator adjusts for this so your final dough hydration is accurate.

**Q: How much starter should I use?**

A: Most recipes use 15 to 25% starter relative to flour weight. Around 20% is the sweet spot for a typical room-temperature bulk ferment of 4 to 6 hours. Use less starter (10-15%) for a longer, more flavorful cold ferment, or more starter (25-30%) if your kitchen is cold or you want a faster rise.

**Q: What does salt percentage affect?**

A: Salt strengthens gluten structure, controls fermentation speed, and adds flavor. The standard range is 1.8 to 2.2% of flour weight. Too little salt and the dough ferments too fast and tastes flat. Too much and it slows fermentation and tastes overly salty. Most bakers use exactly 2%.

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Source: https://vastcalc.com/calculators/health/sourdough
Category: Health & Fitness
Last updated: 2026-04-08