Basic Sourdough Calculator
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
Recipe inputs
Amber fields are editable — the recipe inputs above and the Levain & Final Mix percentages below. Everything else updates instantly in your browser; nothing is uploaded.
Summary
Total Formula
| Ingredient | % | Weight |
|---|---|---|
| Total Flour | 100.0% | 2.006 kg |
| Bread Flour | 53.3% | 1.068 kg |
| Whole Wheat Flour | 46.7% | 0.938 kg |
| Rye Flour | 0.0% | 0.000 kg |
| Water | 76.6% | 1.537 kg |
| Salt | 1.9% | 0.038 kg |
| Levain | 1.0% | 0.020 kg |
| Total | 179.5% | 3.600 kg |
Levain
| Ingredient | % | Weight |
|---|---|---|
| Total Flour | 100.0% | 0.131 kg |
| Bread Flour | % | 0.131 kg |
| Rye Flour | % | 0.000 kg |
| Water | % | 0.131 kg |
| Levain | % | 0.020 kg |
| Total | 215.0% | 0.281 kg |
Final Mix
| Ingredient | % | Weight |
|---|---|---|
| Total Flour | % of final dough | 1.875 kg |
| Bread Flour | % | 0.938 kg |
| Fresh Flour | % | 0.938 kg |
| Multi Grain | % | 0.000 kg |
| Water 1 | % | 1.219 kg |
| Water 2 | % | 0.188 kg |
| Salt | % | 0.038 kg |
| Other 1 | % | 0.000 kg |
| Other 2 | % | 0.000 kg |
| Levain | % | 0.281 kg |
| Total | 192.0% | 3.600 kg |
Process — Levain
- Mix all ingredients until well incorporated with D.D.T. of 28°C / 82.4°F
- Allow to ferment 4 hours at room temperature (21°C / 70°F)
Process — Final Dough
Mix by hand or machine until the dough is moderately developed
- Autolyse
- Flour + water 1 - 1 hour
- Mixing
- Hand mix or machine
- D.D.T.
- 78-80°F
- First fermentation
- 3 hours with 2 folds
- Divide
- 0.900 kg
- Resting time
- 20-25 minutes
- Final shape
- Boule or batard
- Final proof
- 12 – 18 hours cold proof
- Bake
- Bake with steam at the beginning for 20 minutes at 450-485°F, then vent for 20 minutes
Notes
- Hydration may vary with the quality and moisture content of the flour.
- Time and temperature will vary from oven to oven and with the weight of the loaves.
Default weights use the Basic Sourdough formula. Edit the orange Levain and Final Mix percentages to adjust the recipe; hydration and fermentation time vary with flour, room temperature and oven behaviour. Use Reset to restore the original recipe.
How to use this calculator
- Set the number of loaves (Units) and the target weight per loaf (Unit Weight, kg).
- Optionally add a Levain Buffer in kg if you want to build extra levain beyond the recipe.
- Read the scaled Total Formula, Levain build and Final Mix tables, plus hydration and dough-weight summary. Use Reset to restore the original recipe.
How it works
The Basic Sourdough Calculator scales a fixed sourdough formula by loaf count and target loaf weight, keeping the recipe percentages exactly as supplied. It reports total dough weight, prefermented flour, total flour in formula, total levain and hydration alongside the full Total Formula, Levain and Final Mix ingredient tables.
Total dough weight is Units × Unit Weight. The Final Mix flour is derived by dividing the dough weight by the final-mix total percentage, then each ingredient is its baker's percentage of that flour. The levain build is sized from the final-mix levain requirement, and the Total Formula combines the levain and final-mix weights. Hydration is calculated including half the seed levain weight, matching the source workbook.
Worked example
Default recipe — 4 loaves at 0.900 kg. Four loaves at 0.900 kg gives 3.600 kg total dough, 76.7% hydration, 2.006 kg total flour in formula, 0.281 kg total levain and 6.52% prefermented flour. Bread flour is 53.3% (1.068 kg) and whole wheat 46.7% (0.938 kg) of the total formula.
Tips
- All calculations run in your browser. Nothing is uploaded.
- Hydration and fermentation time can vary with flour, room temperature and oven behaviour.
- Weigh ingredients in grams for accuracy — the kg figures convert directly (multiply by 1000).
Frequently asked questions
What is baker's percentage?
Every ingredient is expressed as a percentage of the total flour weight (flour = 100%). It lets you scale a recipe up or down while keeping the same ratios, which is exactly how this calculator works.
What does the Levain Buffer do?
It adds extra levain to build beyond the recipe so you have a little spare. It only changes the Total Levain and Total flour in formula summary figures — it does not alter the loaf recipe itself.
Why is hydration shown as 76.7% and not just the water percentage?
Hydration here includes half of the seed levain weight on both the water and flour side, because the seed levain is roughly equal parts flour and water. This matches the source formula.
Can I change the ingredient percentages?
This Basic build keeps the supplied formula fixed so the outputs match the source recipe exactly. You scale it by loaf count, loaf weight and levain buffer.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.