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Sourdough Calculator

Table of contents

Sourdough calculatorBaker's formula or baker's percentageCalculations to make sourdoughSourdough hydrationSourdough starter and sourdough starter hydrationSourdough fermentationFAQs

Believe it or not, we all have a baker inside us, and our sourdough calculator is just the tool to bring out and practice your baking skills.

No occasion or celebration is complete without a baked good. Whether it is a Christmas dinner or your birthday party, there is always going to be cake, cookies, bread, or pizza.

Whether or not you have decided to make sourdough bread at home, you will want to continue reading if you are curious to know how to calculate water for sourdough or how sourdough fermentation works. Maybe you are familiar with it all and are simply wondering what math goes into the calculations that make sourdough.

Sourdough calculator

Our sourdough calculator is a convenient tool for experts and aspiring bakers alike. Sourdough has to be one of the most important weapons in a baker's arsenal, metaphorically speaking, of course.

The sourdough calculator calculates the ratios of ingredients required to make the perfect sourdough. The main ingredients of sourdough are flour, water, starter, and salt. Along with ratios of the ingredients, our tool determines the starter hydration and its flour and water quantity. And as a bonus, the calculator also displays the total weight of the dough, flour, water, and total hydration.

Many of us have taken up different and new activities during quarantine. One of the most sought-after has to be quarantine food and cooking.

So, if you are making sourdough bread or have decided to be creative and make a sourdough pizza, this tool will help you make well-balanced sourdough.

Baker's formula or baker's percentage

Baker's percentage, or baker's math, is a formula that indicates the proportions of ingredients in baking. These ratios give a well-balanced amount of ingredients.
The baker's math for sourdough is:

  • Flour - 100%;
  • Water - 67%;
  • Starter - 20-25 %; and
  • Salt - 2%.

This means whatever amount of flour you use to make your sourdough, water should be 67% of its weight, the starter 20 to 25%, and the salt 2% of the flour.

Our tool is partially based on baker's math, as we allow the user to enter the amount of water freely and not limit it to 67%, because everyone has their own preference when it comes to the hydration of the sourdough.

Calculations to make sourdough

The sourdough calculator has calculations based on the flour needed to make the sourdough bread.
Based on the amount of flour you are using, the calculator will calculate the amount of hydration, starter, and salt.
Baking usually has specific mixing ratios for different ingredients for the baked good to come out perfect and as desired. And for you to have a better idea, we suggest taking a look at our mixing ratio calculator.

  • How to calculate starter for sourdough?

    The one thing that makes a sourdough actually a sourdough is the starter. In a traditional sourdough, the leavening agent or starter is made using flour and water left to ferment naturally.

    To evaluate the amount of the starter, you may use the following formula:

    starter = 20% × amount of flour

    The starter is 20% of the amount of flour you're using to make your sourdough.

    This amount of the starter significantly varies according to your area's temperature. If you're living in a place with cold temperatures, you may need to increase the amount of the starter, and if you're living in warmer areas, you may need to reduce the amount of the starter.
    Based on the amount of starter you need for your dough, you can also determine how much flour and water you would need with your desired hydration. You may refer to the starter hydration section in the calculator.

  • How to calculate salt for sourdough?

    Usually, the amount of salt in any recipe depends on your individual taste. Still, if you want to follow the proper proportions to make your sourdough, the ratio of salt is supposed to be 2% of the amount of flour you are using.

    salt = 2% × amount of flour

    If you're using 400 grams of flour, you will need 8 grams of salt.

  • How to calculate the total weight of the sourdough?
    The total weight of the sourdough is an estimation of what to expect in terms of the overall combined weight of all the ingredients.
    Total weight = flour + water + starter + salt
    So, to get the total weight of your sourdough, simply sum all the ingredient's quantities.
    For instance, if you are using 500 g of flour, 350 ml of water, 100 g of starter, and 10 g of salt, the total weight of your dough is,
    500 + 350 + 100 + 10 = 960 g

Sourdough hydration

The hydration of a sourdough refers to the total amount of water or moisture present in the dough. It impacts the quality of your dough before and after baking.
Your sourdough can either be low or high hydration. Both have their own virtues and which you choose all comes down to personal preference:

  • Low hydration sourdough
    A low hydration sourdough has less water in it, which makes it easier to handle and kneed because it is less sticky. The fermentation process is slow but the dough rises well while baking.

  • High hydration sourdough
    A high hydration dough, having more water, is more sticky and thus a bit tricky to handle. But the fermentation process is quicker with a thin crispy crust and an open crumb.

Many of you wonder if your dough has the right hydration, but the main thing to remember is that there is no right or wrong hydration. You have to figure out the hydration that works best for you, so take notes of your ingredient ratio, and if you're not happy, change it!

Sourdough starter and sourdough starter hydration

Imagine the starter of sourdough to be what yeast is to regular bread.

Unlike regular bread, which uses yeast as a starter, the starter of sourdough is a fermented mixture of flour and water.
The sourdough starter hydration refers to, as the name indicates, the amount of water in the starter. Since it is a mixture of flour and water, the amount of water can be changed to suit your liking. Our sourdough calculator determines the amount of starter needed in the dough based on the baker's formula. Still, you can also estimate the amount of flour and water needed for your starter based on your chosen hydration.
In the second section of the tool:

  1. Enter the desired hydration of your starter.
  2. Check that the amount of the starter that has been calculated in the first section is correct, or input your own.
  3. The result based on the above two values is:
    i. The amount of flour in grams; and
    ii. The amount of water in milliliters.

You can learn more about yeast and its conversion from dry to active using our yeast converter.

Sourdough fermentation

Sourdough bread is traditionally made using a starter created by natural fermentation instead of using a leavening agent.

The cooking measurements used in our sourdough calculator are in grams and mililiters (for water), but if you're using any other units of measurement, you can still convert them to other units of your liking, such as:


How do I calculate the starter for my sourdough?

The starter is 20% of the amount of flour that you're using to make your sourdough. To calculate the amount of the starter, you may use the following formula:

starter = (1/5) × amount of flour

This amount of the starter significantly varies according to the temperature of your area.

What is the hydration of my sourdough with 800 g of flour?

If you are using baker's percentage to calculate the ratio of ingredients of your sourdough, then the hydration of your dough is 67%. It means you should add 536 ml of water to make your sourdough.

The hydration of sourdough refers to the amount of water present in the dough, and this amount determines the quality, flavor, look, and ease of baking of your dough.

What is sourdough starter?

The starter of the sourdough is a fermented mixture of flour and water. It is the leavening agent of sourdough products. You can imagine it to be the same as what yeast is to regular bread.

The amount of starter needed in sourdough is 20% of the flour, but it also depends on the temperature - higher temperatures require a lesser amount, and lower temperatures require a higher amount of starter.

How much starter should I add to 600 g of flour?

You need 120 grams of starter to add to 600 grams of flour for sourdough. To calculate the amount of the starter, you may use the following formula:

starter = (20 / 100) × amount of flour

The starter is 20% of the amount of flour that you're using to make your sourdough.

How can I calculate sourdough hydration?

Hydration is the ratio of water to flour in the sourdough. This accounts for the total amount of water and flour in the dough and the starter. We can use the following formula to calculate the hydration percentage of sourdough.

Hydration % = total water / total flour × 100

Starter Hydration

Total Dough

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