Baker’s percentages express ingredient weight relative to total flour weight. Add every flour component to establish the 100% basis, then calculate each percentage as ingredient weight divided by total flour weight, multiplied by 100.
Enter the flour basis
For 400 g bread flour and 100 g whole wheat flour, total flour is 500 g. The flour shares are 80% and 20%. Adding 350 g water gives 70% hydration when those are the only flour and water contributions.
Enter each row in grams and assign its role: Flour, Water, Starter, or Other ingredient. Convert a cup quantity using an appropriate reference before entering its weight. The role determines how a row contributes to flour and water totals.
Describe a starter explicitly
If the formula includes a starter or preferment, enter its mass and declared hydration. Hydration means water mass divided by flour mass, expressed as a percentage. A 200 g starter at 100% hydration contributes 100 g flour and 100 g water.
Add those contributions to total flour and total water for the percentage calculation. Keep the starter as a single added ingredient when summing dough weight; do not add its flour and water a second time.
Know what the hydration figure includes
The displayed hydration uses identified water plus declared starter water. It does not assume that the whole mass of milk, butter, honey, or another mixed ingredient is water. Keep such ingredients as their own formula rows.
If you need a composition-based water calculation, that requires additional reliable composition data and a clearly stated method beyond a basic flour-and-water formula.
Set a target dough weight
A formula containing 500 g added flour, 350 g added water, 200 g starter at 100%, and 12 g salt weighs 1,062 g. Its total flour is 600 g and total water 450 g, giving 75% hydration.
A target of 1,593 g is a factor of 1.5: add 750 g flour, 525 g water, 300 g starter, and 18 g salt. Inspect the ingredient totals and target together before using the result.
Keep process decisions separate
The percentages describe weights and ratios. They do not predict fermentation time, proofing readiness, or baking time. Keep the method and any process changes with your recipe notes.