Sourdough Bread Calculator
Use this free sourdough calculator to calculate starter, flour, water, salt, hydration, total dough weight, and loaf scaling. The calculator automatically accounts for starter hydration, making it easier to build accurate sourdough recipes.
Bread dough math, clearly handled
Sourdough Bread Calculator
Build a dough formula by finished loaf weight. The calculator accounts for the flour and water already present in your starter.
Your formula
Ingredients to add
Why these numbers differ: Starter already contains flour and water, so this calculator subtracts those from the final flour and water amounts.
Advanced details
What is in the dough
- Flour in starter
- 0g
- Water in starter
- 0g
- Total flour
- 0g
- Total water
- 0g
- Actual hydration
- 0%
- Total dough weight
- 0g
- Dough per loaf
- 0g
A useful boundary
This calculator handles the math.
Your starter strength, flour, room temperature, and fermentation time still matter. Ingredient amounts are a formula, not a guaranteed schedule.
- The starter defaults to 100% hydration.
- All percentages use total flour as the baker's-percent base.
- Weights are rounded for display; calculations retain full precision.
A typical process might look like this
- Mix flour, water, starter, and salt.
- Rest, then stretch and fold several times.
- Bulk ferment until the dough rises noticeably.
- Shape, proof, and bake in a hot covered pot or Dutch oven.
Watch the dough rather than the clock. Fermentation varies with starter activity and room temperature.
What Does This Sourdough Calculator Do?
Making sourdough bread involves more than simply mixing flour and water. Unlike commercial yeast recipes, sourdough formulas include a starter that already contains both flour and water. This can make recipe calculations confusing, especially when adjusting hydration levels, changing loaf sizes, or scaling recipes up and down.
This Sourdough Calculator automatically calculates the correct amounts of starter, flour, water, and salt needed to reach your desired dough weight and hydration percentage. It also accounts for the flour and water already present in your starter, helping you avoid common calculation mistakes.
With this calculator, you can:
- Calculate ingredient amounts based on desired loaf weight
- Adjust hydration percentages for different dough styles
- Change the number of loaves without doing the math manually
- Account for starter hydration automatically
- See exactly how much flour and water comes from the starter
- View total dough weight and dough weight per loaf
- Experiment with different sourdough formulas quickly and accurately
Whether you’re baking a single loaf for your family or preparing multiple loaves for a gathering, this calculator removes the guesswork and helps you build consistent sourdough recipes with confidence.
What Is Starter Percentage?
Starter percentage is the amount of sourdough starter used in a recipe compared to the total flour in the dough. In baker’s percentages, flour is always considered 100%, and all other ingredients are expressed as a percentage of that flour weight.
For example, if your dough contains 500 grams of total flour and you use 100 grams of starter, the starter percentage is 20%.
Starter percentage affects how quickly your dough ferments. In general:
- 10–15% starter – Slower fermentation, longer rise times, and often more developed flavor.
- 20% starter – A common starting point for many sourdough recipes.
- 25–30% starter – Faster fermentation and shorter rise times.
- Above 30% starter – Very rapid fermentation that may require closer monitoring.
The ideal starter percentage depends on several factors, including room temperature, starter strength, flour type, and your baking schedule. A cool kitchen may benefit from a higher starter percentage, while a warm kitchen may require less starter to prevent over-fermentation.
This calculator uses starter percentage to determine how much starter should be included in the final dough formula. Because starter already contains flour and water, the calculator automatically subtracts those amounts from the flour and water you need to add, helping ensure your hydration and dough weight remain accurate.
Example
Suppose you want to make a dough containing 500 grams of total flour with a 20% starter percentage:
- Total flour: 500g
- Starter percentage: 20%
- Starter required: 100g
If that starter is maintained at 100% hydration, the 100g starter already contains approximately:
- 50g flour
- 50g water
The calculator automatically accounts for those amounts when calculating the remaining flour and water needed for your recipe.
Why Starter Hydration Matters
Starter hydration describes the ratio of water to flour in your sourdough starter. It is expressed as a percentage of the flour weight, just like other baker’s percentages.
A 100% hydration starter contains equal weights of flour and water. For example:
- 50g flour
- 50g water
- Total starter weight: 100g
This is the most common type of starter and is often assumed in sourdough recipes unless otherwise specified.
However, not all starters are maintained at the same hydration level:
- 50–60% hydration – Stiff starters that are firm and dough-like.
- 75–100% hydration – Medium hydration starters commonly used for artisan breads.
- 125%+ hydration – Very liquid starters with a batter-like consistency.
Starter hydration matters because the starter contributes both flour and water to the final dough. If you ignore the hydration of your starter, your actual dough hydration may be very different from what you intended.
Example
Suppose you add 100g of starter to a recipe:
100% Hydration Starter
- 50g flour
- 50g water
50% Hydration Starter
- 66.7g flour
- 33.3g water
Even though both starters weigh 100g, they contribute very different amounts of flour and water to the dough.
As a result, a recipe calculated using a stiff starter may produce a noticeably firmer dough than the same recipe calculated with a liquid starter.
This calculator automatically accounts for starter hydration when determining how much additional flour and water to add. By entering the correct starter hydration, you can maintain your target dough hydration and achieve more predictable results.
Typical Starter Hydrations
| Starter Type | Hydration |
|---|---|
| Stiff Starter | 50–60% |
| Medium Starter | 75–80% |
| Standard Starter | 100% |
| Liquid Starter | 125%+ |
For most home bakers, a 100% hydration starter is the simplest choice because it is easy to feed, easy to calculate, and widely used in sourdough recipes. If you’re unsure what hydration your starter is, 100% is usually a good assumption unless your feeding routine intentionally uses more flour than water.
What Is Dough Hydration?
Dough hydration is the amount of water in a dough compared to the total flour, expressed as a percentage. It is one of the most important factors affecting how bread dough behaves during mixing, fermentation, shaping, and baking.
In baker’s percentages, flour is always considered 100%, and hydration is calculated using this formula:
Hydration%=WaterFlour×100Hydration\% = \frac{Water}{Flour} \times 100
For example, if a dough contains:
- 500g flour
- 350g water
The hydration is:
350 ÷ 500 × 100 = 70%
Higher hydration doughs contain more water and tend to produce a more open crumb with larger air pockets. Lower hydration doughs are firmer, easier to handle, and often create a tighter crumb structure.
Typical Hydration Ranges
| Hydration | Characteristics |
|---|---|
| 50–60% | Very stiff dough, easy to shape, dense crumb |
| 60–65% | Traditional sandwich breads and beginner-friendly doughs |
| 65–75% | Common artisan bread range with good balance of handling and openness |
| 75–85% | Wet, extensible doughs that can produce large open holes |
| 85%+ | Very high hydration doughs requiring advanced handling techniques |
How Hydration Affects Your Dough
As hydration increases:
- Dough becomes softer and stickier.
- Gluten develops differently.
- Shaping becomes more challenging.
- The crumb often becomes more open and airy.
- Steam generation during baking increases.
As hydration decreases:
- Dough becomes firmer and easier to handle.
- Shaping is simpler.
- Loaves tend to hold their shape more easily.
- The crumb is generally tighter and more uniform.
Why Hydration Can Be Confusing in Sourdough
Unlike yeast breads, sourdough recipes include a starter that already contains flour and water. Many simple calculators ignore those contributions, which can result in an actual hydration level that differs from the intended hydration.
This calculator accounts for the flour and water contained in your starter when calculating the final formula. That means the hydration percentage shown represents the hydration of the entire dough, not just the ingredients added during mixing.
A Good Starting Point
For most home bakers, a hydration level between 65% and 75% provides a good balance between dough handling and bread quality. If you’re new to sourdough, starting around 70% hydration is often a comfortable place to learn how dough should feel and behave.
As your experience grows, experimenting with different hydration levels can help you discover the texture, crumb structure, and handling characteristics that best suit your baking style.
Example Sourdough Formula
Let’s look at a practical example of how the calculator works.
Suppose you want to bake one 900g sourdough loaf using:
- 70% hydration
- 20% starter
- 2% salt
- 100% hydration starter
The calculator produces approximately:
| Ingredient | Amount |
|---|---|
| Starter | 104g |
| Flour to Add | 469g |
| Water to Add | 313g |
| Salt | 10g |
| Total Dough Weight | 900g |
What’s Happening Behind the Scenes?
The starter already contains flour and water.
A 100% hydration starter consists of equal parts flour and water, so:
- 104g starter contains about 52g flour
- 104g starter contains about 52g water
The total dough therefore contains:
| Component | Amount |
|---|---|
| Total Flour | 521g |
| Total Water | 365g |
| Salt | 10g |
This produces a hydration of approximately 70%.
How to Scale the Formula
One advantage of using a calculator is that scaling becomes effortless.
If you change the number of loaves from 1 to 2, the ingredient amounts automatically adjust while maintaining the same hydration, starter percentage, and salt percentage.
Instead of calculating everything manually, the calculator keeps the formula balanced regardless of the batch size.
A Typical Baking Process
Once your ingredients are measured:
- Mix the flour, water, starter, and salt.
- Allow the dough to rest briefly after mixing.
- Perform several rounds of stretch-and-folds during bulk fermentation.
- Continue fermenting until the dough has risen noticeably and shows signs of activity.
- Shape the dough and place it in a proofing basket or bowl.
- Allow the dough to proof until ready.
- Bake in a preheated Dutch oven or on a baking stone.
Remember that fermentation times vary greatly depending on:
- Room temperature
- Starter strength
- Flour type
- Dough hydration
For that reason, experienced sourdough bakers often say:
Watch the dough, not the clock.
The calculator can accurately determine ingredient amounts, but the dough itself will tell you when it is ready for the next step.
Does This Tell Me When the Dough Is Ready?
No. This calculator is designed to calculate ingredient amounts, hydration, starter percentage, and dough weight. It cannot determine exactly when your dough is ready to move to the next stage of the baking process.
One of the unique challenges of sourdough baking is that fermentation is influenced by many factors that vary from one kitchen to another. Two bakers can use the exact same formula and experience very different fermentation times.
Factors that affect fermentation include:
- Room temperature
- Starter strength and activity
- Flour type
- Dough hydration
- Dough temperature
- Seasonal changes
- Altitude and humidity
Because of these variables, most sourdough recipes provide estimated times rather than exact schedules.
Watch the Dough, Not the Clock
Experienced sourdough bakers often follow a simple rule:
Watch the dough, not the clock.
A recipe might suggest a four-hour bulk fermentation, but your dough may be ready sooner or may need additional time depending on conditions in your kitchen.
Instead of relying solely on time, learn to recognize the visual and physical signs that indicate fermentation is progressing properly.
Signs Bulk Fermentation May Be Complete
During bulk fermentation, many bakers look for:
- Noticeable increase in volume
- A smoother dough surface
- Small bubbles visible on the surface or sides of the container
- A dough that feels lighter and airier
- Increased elasticity and strength
The exact amount of rise varies by recipe and baking style, but many sourdough bakers look for roughly a 30–75% increase in volume before shaping.
Signs the Final Proof May Be Complete
After shaping, the dough often shows signs such as:
- Slight expansion in size
- A soft, puffy feel
- Surface bubbles in some doughs
- Slow spring-back when gently pressed with a finger
Many bakers use the “poke test” as one indicator. If a lightly floured finger gently presses the dough and the indentation slowly springs back, the dough may be approaching readiness for baking.
The Calculator Handles the Math
This calculator can accurately determine:
- Starter amount
- Flour to add
- Water to add
- Salt amount
- Dough hydration
- Dough weight per loaf
However, fermentation remains a biological process that depends on the health of your starter and the conditions in your kitchen.
Think of the calculator as your recipe designer. It creates the formula. Your dough then tells you when it is ready for the next step.
A Good Starting Point
If you’re new to sourdough baking, don’t worry about achieving perfect timing. Focus on observing how the dough looks, feels, and responds during fermentation. With each bake, you’ll become more comfortable recognizing the signs that indicate when your dough is ready to shape, proof, and bake.
Over time, you’ll find that your eyes and hands become just as important as any calculator.
Common Sourdough Troubleshooting
Even experienced bakers occasionally encounter problems with sourdough bread. The good news is that most issues can be traced back to a few common causes. Understanding what may have gone wrong can help you make adjustments on your next bake.
My Dough Isn’t Rising
If your dough shows little or no rise during fermentation, possible causes include:
- Weak or inactive starter
- Fermentation temperature that is too cool
- Insufficient fermentation time
- Starter used before reaching peak activity
A healthy starter should typically double or even triple in size after feeding and show plenty of bubbles before being used in a recipe.
My Dough Is Too Sticky
Sticky dough is often caused by:
- Very high hydration levels
- Insufficient gluten development
- Warm dough temperatures
- Using flour with lower protein content
If you’re new to sourdough, consider starting with a hydration level around 65–70% until you become comfortable handling wetter doughs.
My Dough Is Too Dry or Stiff
A stiff dough may result from:
- Hydration set too low
- Measuring errors
- Flour that absorbs water aggressively
- Failure to account for starter hydration
Some whole wheat and specialty flours absorb significantly more water than white bread flour and may require hydration adjustments.
My Bread Didn’t Rise Much in the Oven
Poor oven spring can be caused by:
- Underproofing
- Overproofing
- Weak gluten development
- Insufficient steam during baking
- A starter that lacks strength
A properly fermented dough should still have enough energy remaining to expand rapidly during the first stage of baking.
My Bread Is Dense
Dense bread is often linked to:
- Under-fermentation
- Weak starter activity
- Insufficient gluten development
- Dough that was shaped too aggressively
- Low hydration formulas
Dense loaves usually indicate that the dough did not produce or retain enough gas during fermentation.
My Bread Spread Out Instead of Rising Up
A loaf that spreads outward rather than upward may be caused by:
- Overproofing
- Excessively high hydration
- Weak gluten structure
- Insufficient shaping tension
Improving gluten development and creating a tighter final shape often helps improve loaf structure.
My Crumb Has Large Holes and Dense Areas
This is often called a “fool’s crumb” and can occur when:
- Bulk fermentation was incomplete
- Dough was shaped too tightly
- Large gas pockets formed unevenly
While large holes may look impressive, an evenly fermented crumb generally produces better texture and consistency.
My Crust Is Too Pale
A pale crust may result from:
- Baking temperature too low
- Insufficient baking time
- Lack of steam early in the bake
- Under-fermentation
Extending the uncovered portion of the bake often improves crust color and flavor.
My Bread Is Too Sour
If the flavor is more sour than desired, consider:
- Using less starter
- Shortening fermentation times
- Reducing cold-proofing time
- Feeding your starter more frequently
Longer fermentation generally produces stronger sour flavors.
My Bread Isn’t Sour Enough
If you’d like more tang in your sourdough:
- Extend fermentation slightly
- Use a longer cold proof
- Reduce starter percentage
- Experiment with whole grain flours
Flavor development is influenced by both fermentation time and the balance of microorganisms in the starter.
Remember: Every Kitchen Is Different
Sourdough baking combines science, observation, and experience. The same recipe can behave differently depending on your starter, flour, temperature, and environment.
If a loaf doesn’t turn out exactly as expected, don’t get discouraged. Most sourdough bakers improve through repeated baking, small adjustments, and careful observation. Each loaf teaches something new, and over time you’ll learn how your starter and dough behave in your own kitchen.
The calculator can help you build accurate formulas, but experience will teach you how to bring those formulas to life.
Looking for additional bread baking tools?
Try our Bread Toolbox Calculator for hydration, baker’s percentages, recipe scaling, and dough weight calculations, or use our Poolish Calculator to create poolish preferments for artisan breads.
For a complete guide on sourdough bread baking check out King Arthur’s Sourdough Baking!