# Sourdough Calculator — Baker's Percentage

> Enter total flour, hydration, starter, and salt percentages — get exact grams to measure plus the starter's flour + water contribution, no surprises.

Live tool: https://lofttools.com/tools/cooking-tools/sourdough-calculator

Category: Cooking & Kitchen

## How it works

1. **Enter total flour** — Type the total flour weight for the recipe — this includes the flour already inside your starter.
2. **Set hydration, starter and salt** — Hydration is water as a percent of flour (70-80% is standard). Starter is the levain as a percent of flour (20% is typical). Salt is usually 2%.
3. **Read "Measure into the bowl"** — The top card shows the exact grams to weigh out — flour, water, starter and salt — plus the final dough weight.
4. **Check recipe totals if needed** — The second card breaks down total flour, total water, effective hydration, and how much flour / water your starter contributes — so the subtraction is never a surprise.

## FAQ

### Why is "Flour to add" less than "Total flour"?

Baker's percentages count everything in your recipe, including the flour that's already inside your starter. A 100%-hydration starter is 50% flour + 50% water by weight, so a 200 g starter contributes 100 g flour. To avoid double-counting, the calculator subtracts the starter's flour from the total — you only add the rest from the bag.

### What is baker's percentage?

Baker's percentage expresses each ingredient as a percentage of total flour weight. 1000 g total flour at 75% hydration means 750 g total water, and a 20% starter means the recipe uses 200 g of levain.

### What hydration should I use?

Country sourdough is typically 68-78%. Below 65% gives a dense sandwich crumb; 78-85% gives an open ciabatta-style crumb but is harder to handle; 85%+ is pizza / focaccia territory.

### My starter is not 100% hydration — does that matter?

Yes. Open the Advanced panel and set your starter hydration (50-60% for a stiff starter, 125-150% for a liquid levain). The calculator will split your starter's flour and water correctly.

### Can I copy the recipe?

Yes. The Copy recipe button sends the full formatted recipe (measurements + totals) to your clipboard.

### How does the bake-day timeline work?

Bulk fermentation, shape, proof and bake milestones are calculated as hour offsets from mix, assuming a 22 °C kitchen. Bulk shrinks as hydration rises — wetter doughs ferment faster because there is more free water for yeast activity. Use the timeline as a planner, not a strict schedule: starter strength, flour, and room temperature all shift the real numbers.

### What do the colored bar segments represent?

The composition bar shows the share each ingredient contributes to the final dough weight — flour (warm), water (cyan), starter (violet), salt (muted). It's a quick visual sanity check: flour should dominate, water should be about two-thirds of flour at 75% hydration, starter is a sliver, and salt barely registers.

## Privacy

This tool runs entirely in the browser. Files are not uploaded to a server. They never leave the user's device.

## More

- All tools: https://lofttools.com/tools
- Category: https://lofttools.com/tools/cooking-tools
- LLM index: https://lofttools.com/llms.txt