Food & Cooking⏱ 5 min read
How to Calculate Bread Ingredients for Any Loaf Size
Bread recipes are based on percentages of flour weight — once you understand this, you can scale any recipe, adapt hydration, and design your own formulae from scratch.
Bread baking becomes intuitive when you understand baker's percentages — every ingredient expressed as a percentage of total flour weight. This system makes scaling, adapting, and comparing recipes straightforward.
Baker's Percentage Recap
Flour is always 100%.
Every other ingredient is expressed as % of flour weight.
Ingredient % = (Ingredient weight / Flour weight) x 100
Example: 500g flour, 350g water, 10g salt, 5g yeast
Water: 350/500 x 100 = 70%
Salt: 10/500 x 100 = 2%
Yeast (fresh): 5/500 x 100 = 1%
Standard Bread Formulas
Bread TypeHydrationSaltYeast (dried)
Classic white sandwich60-65%2%1%
Sourdough (open crumb)72-80%2%20% starter
Focaccia75-80%2%1%
Ciabatta80-85%2%0.5%
Bagel55-58%2%1.5%
Brioche60%2%2%
Hydration is the most impactful variable. Higher hydration produces a more open, irregular crumb with larger holes; lower hydration produces a tighter, softer crumb easier to slice. Starting at 65% and incrementally increasing is the standard learning path.
Scaling to Any Loaf Size
Step 1: Decide target dough weight
(typical 1kg tin loaf = ~900g dough)
Step 2: Flour weight = Target weight / (1 + sum of % / 100)
For 65% hydration, 2% salt, 1% yeast:
Sum of % = 65 + 2 + 1 = 68
Flour = 900 / (1 + 68/100) = 900 / 1.68 = 535.7g
Step 3: Calculate each ingredient:
Water: 535.7 x 0.65 = 348.2g
Salt: 535.7 x 0.02 = 10.7g
Yeast: 535.7 x 0.01 = 5.4g
Fresh vs Dried vs Instant Yeast Conversion
Fresh yeast : Dried active yeast : Instant yeast
3 : 1.5 : 1
So if recipe calls for:
Fresh 15g = Dried active 7.5g = Instant 5g
Instant yeast can be added directly to flour.
Dried active yeast should be activated in warm water first.
Ideal water temperature for yeast: 35-38C (hand-warm)
Salt: Why 2% Is Near-Universal
Salt strengthens gluten, controls fermentation speed, and provides flavour. Below 1.5% bread tastes flat; above 2.5% yeast is inhibited. The 2% standard emerged through centuries of practical baking — it's close to optimal across nearly all bread types.
Never put salt in direct contact with yeast before mixing — salt draws water from yeast cells through osmosis and can reduce activity. Add them to opposite sides of the flour bowl and mix thoroughly before adding water.