Baker’s percentage: a formula you can scale

In baker’s percentage, the combined flour in a formula is the reference weight and is written as 100%. Each other ingredient is expressed relative to that flour weight.

The basic calculation

Ingredient percentage = ingredient weight ÷ total flour weight × 100. If a dough contains 1,000 g flour and 700 g added water, added-water hydration is 70%. If it also has 20 g salt, salt is 2%.

Flour blends count together. For 700 g bread flour and 300 g whole wheat flour, total flour is 1,000 g. The blend is the 100% reference.

Scale backward from a target dough weight

Add all ingredient percentages as decimals to get the formula multiplier. For 70% water, 20% 100%-hydration starter, and 2% salt:

Multiplier = 1 + 0.70 + 0.20 + 0.02 = 1.92

For 960 g target dough: flour = 960 ÷ 1.92 = 500 g

Added water = 350 g; starter = 100 g; salt = 10 g

Those ingredient weights total 960 g before rounding. A starter at 100% hydration contains 50 g flour and 50 g water in that example. If you want total hydration rather than added-water hydration, include those starter components in the totals. A different starter hydration changes the split.

Rounding and practical use

For small batches, rounding each ingredient can make the displayed sum differ slightly from the target. A scale readable to 0.1 g helps with small salt or yeast quantities. Calculator math gives ingredient weights; it cannot account for dough left in the bowl, evaporation, or your preferred shaping and bake loss.

For background on baker’s math, see King Arthur Baking’s baker’s math explanation.

Try the sourdough calculator to scale a formula, or read the methodology for the site’s calculation assumptions.