The Complete Guide to Baker's Percentages and Dough Hydration
Baker's percentages are the universal language of professional bread baking. Once you understand the system, you can read any recipe at a glance, predict how a dough will handle before mixing it, and confidently scale a formula from a single loaf to a full bakery batch without a spreadsheet.
How to Use This Dough Hydration Calculator
Start in the Global Settings panel. Choose your weight unit (Grams or Ounces), then pick a Scaling Mode. "Total Flour" lets you enter the flour weight directly and all other ingredient weights follow from their baker's percentages. "Target Yield" works backward: enter the total finished dough weight you need, and the calculator finds the exact flour weight required so that all ingredients sum to that target.
In the Formula Builder, adjust the baker's percentage for each ingredient. Edit the percentage and the weight updates in real time. Edit the weight and the percentage back-calculates automatically. The True Dough Hydration readout in Global Settings updates live as you work. The Final Recipe card on the right shows ingredients sorted by category and provides a one-click copy button.
Why Flour is Always 100%
In baker's math, flour is the denominator for every ratio in the formula. No matter how much or how little you use, the flour weight always represents 100%. Every other ingredient is expressed relative to that fixed base. A formula that reads "75% water" always means 75g of water for every 100g of flour, whether you are making a 300g test loaf or a 10kg production batch. The ratios hold constant at every scale.
When a formula uses more than one flour type (for example, 75% white flour and 25% whole wheat), those percentages together sum to 100%. They form the flour base. Any ingredient tagged as Flour type in this calculator contributes to that shared 100% base.
Sourdough Starter and True Hydration
A sourdough starter is not a single ingredient: it is a blend of flour and water. At 100% hydration (equal parts flour and water by weight), 100g of starter contains 50g of flour and 50g of water. Listing it as "100g starter" without splitting it will give you an inaccurate hydration reading.
This calculator decomposes the starter automatically. Enter the starter's hydration percentage on the ingredient row (default: 100%) and the True Hydration readout reflects the actual total water content (added water plus starter water) divided by the actual total flour content (added flour plus starter flour). For most sourdough formulas, true hydration runs several percentage points higher than the apparent hydration shown by the raw ingredient list.
Scaling by Target Dough Yield
Professional bakers often work backward from a target: "I need 2,000g of dough to fill three 650g loaves with pan waste." In Target Yield mode, enter that final weight and the calculator divides it by the sum of all baker's percentages to find the exact flour weight required, then calculates every other ingredient from there. This is how production runs are planned without guessing.