Last updated
How to Use the Sourdough Calculator (5-Min Guide)
Our sourdough hydration calculator takes the guesswork out of baker's percentage math. This guide walks you through every feature.
Getting Started: The Basics
Open the calculator. You'll see: Total Dough Weight (e.g., 800g), Hydration (70-75% for beginners), Levain % (typically 20%), Salt % (usually 2.1%). Adjust sliders—the Dough Recipe card updates instantly.
Understanding the Results
The calculator shows exact weights. It includes flour and water in your starter. Learn the theory in our baker's percentage guide.
Flour Mix and Hydration Adjustment
Whole wheat and rye absorb more water. Select a flour mix—the calculator automatically adds hydration. See our hydration guide.
Multi-Loaf Scaling
Baking 2 or 3 loaves? Change "Number of Loaves." All ingredients scale. Percentages stay the same.
Starter Maintenance Tab
Enter current starter amount, desired amount, and feeding ratio (1:1:1, 1:2:2). See our feeding schedule guide.
Temperature and Fermentation Time
Set dough temperature. The calculator estimates bulk fermentation. Watch for ~50% volume increase. Use the built-in timer. Don't rely on time alone.
Save, Export, and Make Bread
Save recipes. Export to PDF. Tap "Make bread" for step-by-step instructions. Use with our hydration and starter ratio guides.
Frequently Asked Questions
Enter target weight, set hydration and levain %, read the amounts. It does the math automatically.
Yes. It accounts for flour and water in your levain. Set levain %—it computes everything.
Yes. Use "Number of Loaves." All ingredients scale; percentages stay the same.
Whole grains need more water. Select a flour mix—the calculator auto-adjusts hydration.
Estimates bulk fermentation based on temperature. Use as a guide—watch for 50% rise.
The calculator turns a target loaf weight, a hydration percentage, and a starter ratio into exact gram weights for flour, water, salt, and active starter. Below: how to read each number, common input mistakes, and answers to the questions readers ask most.
Three input mistakes that produce a confusing recipe
- Forgetting starter contributes flour and water. A 100 g starter at 100 % hydration is 50 g flour + 50 g water. The calculator subtracts both from the recipe total — your "Flour" line is therefore lower than 70 % of the loaf weight. This is correct, not a bug.
- Setting hydration above the flour can hold. White bread flour tops out around 78 %. Above that, the dough is soup. The calculator caps each calculator at the safe range; if you push past, expect to add an extra autolyse and gentle shaping.
- Picking 0 % закваска by accident. A levain percentage near zero gives you a recipe that ferments for 18+ hours. Most home bakers want 15–25 %; commercial bakeries use 8–15 % with longer cold proofs.
Reading the output card
- The salt looks too small. Salt is 1.8–2.2 % of total flour. On a 460 g flour recipe, that is 8–10 g — looks tiny but is exactly right. Less and the loaf is bland; more inhibits fermentation.
- The starter looks too large. A 100 g starter on an 800 g loaf (~12 %) is the everyday default. Bigger starters speed fermentation; smaller ones slow it. Adjust the slider to match your schedule.
- I want to share a recipe. Use the "Share" link to copy a URL with the recipe parameters baked into query params. The recipient sees the exact same recipe — no signup, no backend.
Calculator FAQ
Yes. Flour is 100 %, every other ingredient is expressed as a percentage of flour weight. This is the same system professional bakeries use.
Yes — pick the flour mix in the wizard and the calculator auto-adjusts hydration based on each flour's absorption. Whole wheat adds about 7 %, rye 5–12 %, spelt 3 %.
65 % for a firm everyday loaf, 72 % for a balanced open crumb, 80 %+ for an artisan loaf with big holes. Beginners do best at 70–72 %.
Yes — set your starter hydration in step 1. Most home bakers run a 100 % starter (equal flour and water by weight); the calculator subtracts the right flour and water from the totals.
Yes — change the loaf weight or loaf count and the calculator rescales every ingredient proportionally. Scaling stays accurate from 200 g rolls to 4 kg multi-loaf bakes.
Related guides
Disclaimer: Baking results vary based on flour type, ambient temperature, starter health, and technique. Use this guide and our sourdough hydration calculator as a starting point, then adjust to your conditions.