Bakers describe dough by its hydration — water weight as a percentage of flour weight. Get it into a spreadsheet and you can dial in any loaf or scale a formula with confidence.
In baker's math flour is always 100%, and every other ingredient is a percentage of it.
The example
A dough uses 1000 g of flour and 700 g of water.
| A | B | |
|---|---|---|
| 1 | Ingredient | Grams |
| 2 | Flour | 1000 |
| 3 | Water | 700 |
| 4 | Hydration | 70% |
The formula
Water as a fraction of flour weight:
How it works
The baker's-math logic:
- Flour is the baseline, treated as 100% (B2).
- Water weight (B3) is divided by flour weight to express it relative to flour.
B3/B2= 700/1000 = 0.70; format as a percentage to read 70%.- Higher hydration means wetter, more open-crumb dough (ciabatta ~80%, sandwich bread ~60%).
Other ingredients follow the same rule: salt grams ÷ flour grams gives the salt percentage.
Try it: interactive demo
Enter flour and water in grams — see the hydration percentage.
Variations
Water needed for a target hydration
Flip the math to find the water for a hydration you want.
Salt percentage
Same baker's-math idea for salt against flour.
Pitfalls & errors
Baker's percentages are by weight, not volume. Weigh ingredients in grams for accuracy.
If you use a preferment (poolish, levain), include its flour and water in the totals before computing hydration.
Practice workbook
Frequently asked questions
Why is flour always 100%?
What hydration should I use?
Do I include preferment water?
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