Recipe Scaler

Scale a full sourdough recipe to any size — enter your target hydration, salt, and starter percentages, and either a total flour weight or a target dough weight.

Percentages are baker’s percentages: everything is a share of total flour weight, including the flour inside your starter. Careful copying a percentage off a recipe you found elsewhere: some sites print “levain %” against just the flour added at mix, not total flour including the starter itself — those are different numbers, and using the wrong one here changes how much starter you’re really adding. If a recipe gives you the starter’s weight directly instead of a percentage, divide it by the total flour weight and multiply by 100 to get the number this field wants.

Flour to add
900 g
Water to add
650 g
Starter
200 g
Salt
20 g
Total flour
1000 g
Total dough weight
1770 g
Prefermented flour (PFF)
10%
  1. Total flour: 1000 g (given)
  2. Starter: 1000 × 20% = 200 g (100 g flour + 100 g water at 100% hydration)
  3. Flour to add at mix: 1000 − 100 = 900 g
  4. Total water: 1000 × 75% = 750 g
  5. Water to add at mix: 750 − 100 = 650 g
  6. Salt: 1000 × 2% = 20 g
  7. Total dough weight: 900 + 650 + 200 + 20 = 1770 g
  8. This is raw dough weight -- expect roughly 10-20% loss by the time it's a baked loaf (moisture loss in the oven), more for a free-standing/hearth loaf, less for a pan loaf.
  9. Prefermented flour (PFF): 100 ÷ 1000 = 10%

Frequently asked questions

What are baker's percentages?
Every ingredient expressed as a percentage of total flour weight, with flour itself as 100%. It's how professional bakers scale recipes to any size without recalculating every ratio by hand.
Why does total flour include the flour inside my starter?
Your starter is itself flour and water. Counting it as part of the 100% flour baseline (rather than adding it on top) is what lets the hydration and salt percentages describe the whole dough accurately, not just what you add at final mix.
Can I scale from a dough weight I want, instead of a flour weight?
Yes — switch "Start from" to total dough weight (useful when you know your pan or basket needs a specific weight) and it works backward to the flour weight for you.