Your result
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Enter your values, then click Calculate result.How this calculator helps
Scale sourdough dough weight, hydration, prefermented flour and salt while accounting for the flour and water already in your starter. Every percentage on this page refers to total flour in the finished dough. That includes the flour hidden inside ripe starter. Total dough weight includes flour, water and salt, so dividing final weight by one plus the hydration and salt fractions first finds the flour budget. This distinction matters when scaling a loaf: simply taking 70% of the target dough weight would produce far too much water. All ingredient outputs are grams.
How to use it
- 1
Choose the stated method or shape and read the labels before replacing the example values.
- 2
Enter the measurements in the exact units shown. Use the inputs described in the methodology below.
- 3
Click Calculate result. Editing inputs keeps the previous submitted result visible until you calculate again.
- 4
Compare the supporting figures with the formula and worked example, then review the method’s specific limitations.
Formula and methodology
Total flour = dough weight ÷ (1 + hydration fraction + salt fraction). Starter flour = total flour × prefermented flour fraction. Subtract starter flour and starter water from the final totals.
The calculator applies the displayed arithmetic to the values entered on this device. It does not silently load a local tax rate, currency conversion or commercial assumption.
Worked calculation example
For 1,000 g dough, 70% hydration, 20% prefermented flour, 2% salt and a 100%-hydration starter: add 465.12 g flour, 290.70 g water, 232.56 g starter and 11.63 g salt.
How to interpret your result
This method applies only within the stated scope. Four-ingredient mass balance only. No fermentation schedule, food-safety judgment or baked-weight prediction. Added inclusions and handling losses require separate accounting. The worked scenarios below identify the measurements and conventions needed to interpret the displayed output.
For different inputs or formulas, use Ratio Calculator; Weighted Mean Calculator; Unit Price Comparison Calculator.
Related questions this calculator covers
- sourdough calculator
Scenario comparison
| Scenario | What it shows |
|---|---|
| 1,000 g, 70% hydration, 20% prefermented flour | 465.12 g new flour and 290.70 g new water with 100%-hydration starter. |
| Same formula, 2,000 g dough | all ingredient masses double; fermentation time does not automatically double. |
| Zero prefermented flour | no starter contribution; this is only a flour-water-salt mass balance, not a sourdough fermentation recipe. |
Common mistakes to avoid
- Calling starter mass percentage prefermented flour percentage.
- Excluding starter water from final hydration.
- Treating ingredient scaling as a proofing-time recommendation.
Reproduce the equation shown on this page using the same entered values. For 1,000 g dough, 70% hydration, 20% prefermented flour, 2% salt and a 100%-hydration starter: add 465.12 g flour, 290.70 g water, 232.56 g starter and 11.63 g salt. Keep input units and the selected method with any recorded result. Check unusual measurements rather than relying on extra displayed decimal places.
Four-ingredient mass balance only. No fermentation schedule, food-safety judgment or baked-weight prediction. Added inclusions and handling losses require separate accounting.What can affect the result?
Prefermented flour versus starter weight
Prefermented flour is the share of total flour that arrives through the starter. It is not the weight of starter divided by new flour. A 100%-hydration starter contains equal weights of flour and water. At 20% prefermented flour, starter mass is therefore 40% of total flour. If a recipe says 20% starter by mass, convert its convention before entering it. Otherwise you will unintentionally change inoculation and fermentation behavior.
Stiff and liquid starters
Starter hydration describes starter water divided by starter flour. A stiff 50%-hydration starter contributes less water than a liquid 100%-hydration starter for the same prefermented flour amount. The calculator subtracts the actual contribution from the water to add. If that contribution exceeds the requested final water budget, it reports an invalid combination. It does not suggest draining starter or quietly replacing a negative water quantity with zero.
Scaling a batch and dividing loaves
Enter the combined dough weight for the entire batch. For two 750 g loaves, use 1,500 g, then divide the mixed dough after allowing for your handling losses. Scaling changes ingredient quantities but does not automatically preserve proofing time. Dough temperature, starter maturity, flour strength and kitchen conditions still matter. Optional fats, seeds and other additions are outside this four-ingredient mass balance; account for them separately when targeting exact finished dough weight.
Privacy and browser processing
Values entered on this page are processed in the current browser session. SolvePilot does not require an account and does not receive the values entered into the calculator. Refreshing or closing the page clears the working values unless the browser itself restores a previous session. Avoid entering identifying or account information because the calculation needs summary values only.
Accuracy and verification
Accuracy depends first on input quality. Confirm definitions, scales, dates and source information before entering a value. Keep an independent record of any result used for planning because this page does not create an official statement or retain a calculation history.
Limits of this estimate
Four-ingredient mass balance only. No fermentation schedule, food-safety judgment or baked-weight prediction. Added inclusions and handling losses require separate accounting.
Sources and review information
Frequently asked questions
Does hydration include starter water?＋
Yes. Both the water and flour in starter are included in final hydration. The displayed water to add is the final water budget minus starter water, so it is often smaller than a simple percentage of new flour.
Is 20% starter the same as 20% prefermented flour?＋
No. Prefermented flour measures flour inside the starter. With 100%-hydration starter, 20% prefermented flour produces starter mass equal to 40% of total flour. Check which convention your recipe uses.
Can I use a stiff starter?＋
Yes. Enter its actual hydration, such as 50%, and the calculator adjusts the starter mass and added water accordingly. Use weighed feed amounts when calculating hydration; volume measurements are not sufficiently consistent for this mass balance.
Why is the water combination rejected?＋
Your starter already contains more water than the finished hydration permits. Reduce prefermented flour, use a stiffer starter or increase final hydration according to the recipe you intend to bake. Negative added water is not a valid ingredient quantity.
Does this determine fermentation time?＋
No. Inoculation influences fermentation, but temperature, flour and starter activity also matter. These outputs are an ingredient scale. Observe the dough and follow a reliable baking process rather than treating an ingredient calculation as a proofing schedule.