What does 70% hydration mean?

It means the water weighs 70% of the flour. With 1,000 g of flour you add 700 g of water. Counting the starter's own water, the true figure is a little higher.

Do I count the starter in baker's percentage?

List the starter as its own line (often 10 to 25% of the flour), and for hydration split it into its flour and water. A 100% starter adds equal amounts of each.

Why do the percentages add up to more than 100?

Because flour alone is 100% and everything else is added on top. A formula totalling 197% makes 197 g of dough for every 100 g of flour.

Can Farinu turn my sourdough formula into a price?

Yes. Enter the recipe with its weights and yield, add your starter as a sub-recipe if you like, and Farinu gives the cost per loaf and a suggested price. On Team, the AI assistant can also import a recipe from a photo or spreadsheet.

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Sourdough calculator: baker's percentage and hydration

A sourdough calculator rests on one rule: flour is always 100%, and every other ingredient is its weight divided by the flour weight, times 100. So 1,000 g of flour with 750 g of water is a 75% dough, and 20 g of salt is 2%. To count hydration honestly, split your starter into the flour and water it contains. Below are the formulas step by step, a worked loaf, and how to scale it to any batch size.

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Worked example: a 75% sourdough, two loaves

Example numbers only. The starter is kept at 100% hydration, so it is half flour and half water.

Bread flour: 1,000 g (100%)
Water: 750 g (75%)
Starter at 100% hydration: 200 g (20%)
Salt: 20 g (2%)
Total dough: 1,970 g, two loaves of 985 g
Flour inside the starter: 100 g
Water inside the starter: 100 g
Total flour: 1,000 + 100: 1,100 g
Total water: 750 + 100: 850 g
True hydration: 850 / 1,100 x 100: 77.3%

The recipe reads as 75%, but the dough behaves like 77%. That gap is why a loaf can feel wetter than the formula promised.

How the sourdough calculator works, step by step

Baker's percentage expresses a formula relative to flour instead of the total weight. It lets you compare recipes, spot a wet or salty dough at a glance, and scale without rounding errors creeping in.

Weigh all flour in the recipe. If there are several flours (bread, whole wheat, rye), add them: together they are 100%.
For each other ingredient, divide its weight by the total flour weight and multiply by 100.
For true hydration, add the starter's flour to the flour and its water to the water. A 100% starter is half and half; a 50% starter is two parts flour to one part water.
Divide total water by total flour and multiply by 100. Count milk at roughly 85 to 90% water if you use it.
Add all the percentages together: that sum is the dough weight for every 100 g of flour.

Scaling: from percentages to any batch size

Once a formula is in baker's percentages, scaling is one division. Decide the total dough you need, divide it by the sum of the percentages, and you have the flour weight. Every other ingredient follows from it.

Say you need three loaves of 900 g, so 2,700 g of dough. The formula above adds up to 197% (100 + 75 + 20 + 2). Flour is 2,700 / 1.97 = 1,371 g. Water is 75% of that, 1,028 g. Starter is 20%, 274 g. Salt is 2%, 27 g. Together they make 2,700 g, with no guesswork.

Weigh a little extra for what sticks to the bowl and bench, around 1 to 2%, if your loaves come out light.

Common hydration levels and what they feel like

These are rough ranges with bread flour. Whole wheat and rye drink more water, so the same dough needs a higher percentage to feel the same.

Typical hydration by bread style (approximate)
Hydration	Typical bread	How the dough handles
60 to 65%	Sandwich loaves, bagels, pretzels	Firm, easy to shape
68 to 72%	Everyday sourdough, country loaf	Soft but manageable
75 to 80%	Open-crumb sourdough	Sticky, needs folds and practice
80% and up	Ciabatta, focaccia	Very slack, baked in a pan or handled wet

From baker's percentage to cost per loaf

If you sell bread, the same weights tell you what a loaf costs. Using the three-loaf batch: 1,371 g of flour at $1.10 a kilo is $1.51. The 274 g of starter is about 137 g of flour, another $0.15. Salt is a few cents. Ingredients come to about $1.70, or $0.57 a loaf, in this example.

That is only the start. Bags, your hands-on time, the oven and a share of rent usually cost more than the flour. Farinu costs a recipe with all of them: ingredients, packaging, sub-recipes like your starter or a levain, labour, machines and overhead, then suggests a price for your target markup, and flags the products that sell below target after a flour price rise. Costing is free for up to 10 recipes.

Questions

What does 70% hydration mean?: It means the water weighs 70% of the flour. With 1,000 g of flour you add 700 g of water. Counting the starter's own water, the true figure is a little higher.
Do I count the starter in baker's percentage?: List the starter as its own line (often 10 to 25% of the flour), and for hydration split it into its flour and water. A 100% starter adds equal amounts of each.
Why do the percentages add up to more than 100?: Because flour alone is 100% and everything else is added on top. A formula totalling 197% makes 197 g of dough for every 100 g of flour.
Can Farinu turn my sourdough formula into a price?: Yes. Enter the recipe with its weights and yield, add your starter as a sub-recipe if you like, and Farinu gives the cost per loaf and a suggested price. On Team, the AI assistant can also import a recipe from a photo or spreadsheet.

Know what each loaf costs, not just how it rises

Put your sourdough formula into Farinu and get the cost per loaf, a suggested price and an alert when a flour price rise pushes a loaf below your target. Free for up to 10 recipes.