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MarginCub

Sourdough calculator

Turn baker's percentages into grams. Enter the number of loaves, the dough weight, and your hydration, starter and salt percentages to get the grams of each ingredient to weigh. The flour and water in the starter are counted, so the hydration you enter is the dough's true hydration.

900 g of dough bakes into a loaf of about 770-800 g.

Water as % of total flour, starter included.

Starter as % of total flour.

100% = equal flour and water.

Your recipe in grams

Flour
915 g
Water
661 g
Starter
203 g
Salt
20 g

Total dough: 1800 g, with 1017 g of flour and 763 g of water including the starter.

What a loaf costs and what to charge

Ingredient cost, all loaves
$2.27
Per loaf
$1.14
Market price per loaf
$9.00
ingredients are 12.6% of the price

Market price assumes $8.00 for a loaf made with 1 lb (454 g) of flour, the farmers market price on our sourdough cost page, scaled to the flour in your loaf and rounded to the nearest 50 cents. Ingredients are a small part of a loaf's price; most of it pays for the oven, bags, stall fee and your time over a ferment of 20-plus hours. Price your sourdough with every cost →

How the sourdough calculator works

Everything is a percentage of the total flour, the flour inside the starter included. That makes the hydration and salt you enter true for the finished dough, whatever starter you use.

Total flour = dough weight ÷ (1 + hydration + salt)

Starter = total flour × starter %

Flour in starter = starter ÷ (1 + starter hydration)

Flour to add = total flour − flour in starter

Water in starter = starter − flour in starter

Water to add = total flour × hydration − water in starter

Worked example - 2 loaves of 900 g

The recipe the calculator opens with: 75% hydration, 20% starter at 100% hydration, 2% salt.

IngredientBaker's %Grams
Total flour, starter included100%1017 g
Total water, starter included75%763 g
Flour to add90%915 g
Water to add65%661 g
Starter20%203 g
Salt2%20 g
Total dough177%1800 g

Grams are rounded, so the total may be off by a gram or two.

Sourdough hydration by loaf

LoafHydrationWhat to expect
Sandwich loaf or first bake65-70%Firm, easy to shape, tight crumb
Everyday artisan boule or bâtard72-78%Soft, holds its shape, open crumb
Open crumb, ciabatta style80-85%Slack, needs strong flour and folds
Lots of whole wheat or rye+5-10 percentage pointsBran absorbs more water

Sourdough calculator FAQ

How do you calculate a sourdough recipe?
Start from the dough weight you want and the baker's percentages, written as decimals: total flour = dough weight ÷ (1 + hydration + salt). 900 g of dough at 75% hydration and 2% salt has 900 ÷ 1.77 = 508 g of flour, 381 g of water and 10 g of salt. The starter is part of that flour and water. At 20%, the starter is 102 g, half flour and half water at 100% hydration, so you add 458 g of flour and 331 g of water.
What are baker's percentages?
Every ingredient is written as a percentage of the flour weight, with the flour at 100%. 75% water means 750 g of water for every 1000 g of flour. Because the flour is the base, the percentages add up to more than 100 and the recipe scales to any batch by changing one number, the flour weight.
Does the calculator count the flour and water in the starter?
Yes. The hydration you enter is the hydration of the finished dough, with the starter's flour and water included. Many recipes leave the starter out, so a recipe that says 75% water with a 20% starter at 100% hydration is really closer to 77% hydration. Set the starter hydration to match yours: 100% for equal flour and water, 50% to 60% for a stiff starter.
How much starter should I use for one loaf?
The common range is 15% to 25% of the flour; 20% is a typical starting point. That is 100 g of starter for 500 g of flour, about one 900 g loaf. Less starter slows bulk fermentation (the first rise), which helps on a warm day or for an overnight rise; more starter speeds it up, which helps in a cold kitchen. If your recipe gives the starter as a percentage of the flour you add rather than of all the flour, enter a little less here: 20% of the added flour is about 18% of all the flour.
What hydration should sourdough be?
At 65% to 70% the dough is easy to shape and bakes into a tighter crumb, good for sandwich loaves and first bakes. 72% to 78% is the usual artisan loaf with a more open crumb. From 80% the dough gets slack and needs strong flour and practice. If whole wheat or rye makes up a large share of your flour, add 5 to 10 percentage points: they absorb more water.
How much salt goes in sourdough?
2% of the total flour is standard; most recipes use 1.8% to 2.2%. For a loaf with 500 g of flour that is 10 g of salt.
How much does it cost to make a loaf of sourdough?
About $1.14 of flour and salt for a 900 g loaf, with flour at $5.00 per 5 lb bag. Water costs next to nothing and the starter is counted as the flour it is made of; the sourdough cost page lists a starter feeding as its own line, which is why it shows a little more for a smaller loaf. The oven, bags and your time are extra; see the full sourdough bread cost breakdown to price those.

Selling your bread? The bakery pricing formula →