How baker’s percentages work
In a baker’s formula, total flour weight is the reference point: 100%. Divide each other ingredient’s weight by total flour weight and multiply by 100. This is different from a percentage of total dough weight.
A source-backed example
King Arthur Baking’s professional reference uses 50 lb flour, 33 lb water, 1 lb salt and 0.6 lb yeast. These become 100%, 66%, 2% and 1.2%. Total dough is 169.2% of flour weight. The default inputs use the same ratios at a smaller scale.
Scaling to a target dough weight
The scale factor is desired dough weight divided by current dough weight. Multiply every ingredient, including flour, by that factor. Multiple flours belong together in the total flour field. Use a consistent weight unit; cups and counts cannot be compared directly.
What the formula does not predict
Water percentage here counts the weight of your water line. It does not infer moisture from eggs, milk or butter, or split a preferment into flour and water. Break those into component weights when you need total hydration. Mixing and baking times do not scale with weight.