Sourdough Calculator
Calculate flour, water, starter, and salt quantities for sourdough bread based on desired dough weight and hydration.
This free online sourdough calculator provides instant results with no signup required. All calculations run directly in your browser — your data is never sent to a server. Enter your values below and see results update in real time as you type. Perfect for everyday calculations, homework, or professional use.
Minimum: 0
Desired total dough weight in grams
Water as % of flour (65-80% typical)
Starter as % of flour (15-25% typical)
Salt as % of flour (1.8-2.2% typical)
Results
Flour
508 g
Water
381 g
Starter
102 g
Salt
10.2 g
How to Use This Calculator
Enter your input values
Fill in all required input fields for the Sourdough Calculator. Most fields include unit selectors so you can work in your preferred unit system — metric or imperial, whichever matches your problem.
Review your inputs
Double-check that all values are correct and that you have selected the right units for each field. Incorrect units are the most common source of calculation errors and can produce results that are off by factors of 2, 10, or more.
Read the results
The Sourdough Calculator instantly computes the output and displays results with units clearly labeled. All calculations happen in your browser — no loading time and no data sent to a server.
Explore parameter sensitivity
Try adjusting individual input values to see how the output changes. This is a quick and effective way to develop intuition about how different parameters influence the result and to identify which inputs have the largest effect.
Formula Reference
Sourdough Calculator Formula
See calculator inputs for the governing equation
Variables: All variables and their units are labeled in the calculator interface above. Input fields accept values in multiple unit systems — select your preferred unit from the dropdown next to each field.
When to Use This Calculator
- •Use the Sourdough Calculator when you need accurate results quickly without the risk of manual computation errors or unit conversion mistakes.
- •Use it to verify calculations made by hand or in spreadsheets — an independent check can catch errors before they lead to costly decisions.
- •Use it to explore how changing input parameters affects the output — a quick way to develop intuition and identify the most influential variables.
- •Use it when collaborating with others to ensure everyone is working from the same numbers and applying the same assumptions.
About This Calculator
The Sourdough Calculator is a free, browser-based calculation tool for engineers, students, and technical professionals. Calculate flour, water, starter, and salt quantities for sourdough bread based on desired dough weight and hydration. It implements standard formulas and supports both metric (SI) and imperial unit systems with automatic unit conversion. All calculations are performed instantly in your browser with no data sent to a server. Use this calculator as a quick reference and sanity-check tool during design, analysis, and learning. Always verify results against primary engineering references and applicable standards for any safety-critical application.
About Sourdough Calculator
Sourdough baking relies on precise ratios, and baker's math makes scaling recipes effortless. Instead of fixed amounts, every ingredient is expressed as a percentage of the flour weight. This calculator takes your desired total dough weight and the key percentages -- hydration, starter, and salt -- then calculates the exact gram weight of each ingredient. A hydration of 75 percent means the water weighs 75 percent of the flour weight. A starter percentage of 20 percent means the starter weighs 20 percent of the flour weight. This system allows you to scale any recipe to any size while maintaining the same proportions and consistent results.
The Math Behind It
Formula Reference
Baker's Math
Flour = Total Dough / (1 + Hydration% + Starter% + Salt%)
Variables: All percentages expressed as decimals relative to flour weight.
Worked Examples
Example 1: 1 kg sourdough loaf at 75% hydration
Dough = 1000g, Hydration = 75%, Starter = 20%, Salt = 2%
Use 508g flour, 381g water, 102g starter, and 10.2g salt.
Common Mistakes & Tips
- !Confusing baker's percentage with true percentage -- baker's percentages can exceed 100% because they are relative to flour, not total.
- !Not accounting for the flour and water within the starter when doing precise calculations.
- !Using too much starter in warm weather, causing over-fermentation and a gummy crumb.
- !Not weighing ingredients on a scale -- volume measurements are too imprecise for bread baking.
Related Concepts
Used in These Calculators
Calculators that build on or apply the concepts from this page:
Frequently Asked Questions
What hydration should I use?
Start at 70-75% for a manageable dough that produces a moderately open crumb. As your skills improve, try 78-85% for a more open crumb. Lower hydration (60-65%) is better for sandwich bread.
How much starter should I use?
15-20% of flour weight is standard. Use less starter (10-15%) for longer fermentation and more complex flavor, or more (25-30%) for faster fermentation in cool environments.