Baker's percentage, explained
Baker's percentage is how professional bakers write recipes. Every ingredient is expressed as a percentage of the total flour weight. Flour is always 100%. Water at 72% means 72g of water for every 100g of flour. Salt at 2% means 2g of salt for every 100g of flour.
Why bakers do it this way
It scales effortlessly. Whether you're baking one 800g loaf or twenty 1kg loaves, the percentages stay the same - you just multiply the flour weight. It also makes recipe comparison meaningful: when someone says "75% hydration", you know exactly what they mean regardless of batch size.
The standard sourdough percentages
- Flour: 100% - by definition.
- Water: 60–85% - depending on the crumb you want and the flour you're using.
- Starter: 10–30% - most home bakers settle in at 15–25%.
- Salt: 2% - universal.
Solving for flour weight from total dough weight
If you know what your finished dough should weigh (e.g. 800g for one loaf), and you know your hydration and starter percentages, you can solve for flour:
flour = totalDough / (1 + hydration + starterPct + 0.02)
That's the formula our calculator uses. Once you have flour weight, the rest is multiplication.