Sourdough Calculator: Baker's Percentages & Hydration Tool

Use this free sourdough calculator to build your sourdough bread recipe in seconds. Adjust hydration, starter percentage, flour, and salt amounts, all calculated instantly using baker's percentages.

Tip: You can save it to your phone's home screen for quick access anytime you bake. Watch these short videos for step-by-step instructions:

• iPhone users: Follow the steps in this video.
• Android users: Watch this video.

Sourdough calculator

What is a sourdough calculator?

A sourdough calculator is a tool for creating a bread formula using baker's percentages.

But unlike most sourdough calculators out there, this one does more than just basic math. It lets you:

• Blend flours: Calculate the exact weight of each flour in your custom mix.
• Adjust hydration: Set your ideal dough hydration with precision.
• Plan your levain: Calculate the amount of levain/active starter you need based on your feeding ratios.
• Account for losses: Adjust levain/active starter weight to cover the bit lost when transferring between jars.
• Total dough weight: Instantly see how much dough you will make.
• Total hydration: This includes the water already in your starter to give you true total hydration.

How to use the sourdough calculator (step-by-step)

1. Set your flour base

1. Enter the desired total flour weight in grams at the top.
2. Adjust the individual flour percentages to create your custom mix. Make sure the total flour equals 100%.

2. Choose your hydration and salt

1. Set your preferred hydration level. If you are new to sourdough, don't exceed 70% hydration.
2. Adjust salt percentage as needed. 2% is a standard starting point.

3. Customize your starter (levain)

1. Enter the percentage of levain/active starter you plan to use. Most recipes use around 20%.
2. By default, the calculator uses the starter at 100% hydration (equal parts water and flour).
3. Use the feeding ratio section to adjust the flour ratio. The water ratio will automatically match the flour to keep the starter at 100% hydration.

Bonus: The calculator also calculates adjusted weights, with an extra 10% to cover transfer losses when moving your starter between containers.

4. Review your results

Once your numbers are set, scroll down to view the calculated results, including:

1. Total dough weight: The final weight of your dough, shown in grams.
2. Total hydration: The overall hydration level, including water from both the dough and your levain/active starter, shown as a percentage.
3. Bread formula: A full, clear breakdown of all ingredients, measured in grams.

All numbers update instantly as you change values, so you can experiment freely and see results in real time.

If you want to use the adjusted weights for the levain ingredients (which include an extra 10% to account for transfer loss), refer to the calculation above.

Real-life example

Let's say you want to make a single loaf using:

• 500g flour
• 70% hydration
• 20% levain/active starter
• 2% salt

Here is what the calculator gives you:

• Total dough weight: 960g
• Total hydration: 72.7%
• Bread flour: 500g
• Water: 350g
• Levain/active starter: 100g
• Salt: 10g

If you need to bake 3 loaves, change the flour amount. The calculator will handle the math. Also, read how to scale a sourdough bread recipe.

Common beginner mistakes (and how to avoid them)

• Forgetting to include the starter's water and flour: Remember, a 100% hydration starter is made with equal parts of flour and water. The calculator takes this into account. There is no need to manually subtract or adjust.

• Misunderstanding percentages: Baker's percentages are always based on the total flour, which is always 100%. So, 70% hydration means 70% of the flour weight, not the total dough weight.

• Trying to eyeball it: Accurate baking starts with a kitchen scale. Even small measurement errors in hydration can change the final texture of your loaf.

Ready to bake?

Scroll back up to the calculator, plug in your numbers, and start building your perfect sourdough loaf. If you are not sure where to begin, try this beginner-friendly formula:

• 500g bread flour
• 340g water (68% hydration)
• 100g levain/active starter (20%)
• 10g salt (2%)

And if you have not yet created a starter, this comprehensive guide will walk you through how to make a sourdough starter from scratch.

What's next?

If you are new to sourdough baking, start with my Beginner's Sourdough Guide. It will guide you through the basics, from creating a sourdough starter to baking your very first loaf.