# Sourdough Calculator

URL: https://speedycalculator.com/calculators/food/sourdough/
Last updated: 2026-10-30

> The sourdough calculator works out the flour, water, starter (levain) and salt for any number of sourdough loaves of a given weight – from your chosen hydration, starter percentage, salt percentage and starter hydration – including the true total hydration.

## Inputs

- Number of loaves
- Dough weight per loaf (g, oz, lb, kg)
- Hydration (of total flour) (%)
- Starter (% of total flour) (%)
- Starter hydration (%)
- Salt (% of total flour) (%)

## Results

- Total flour (including starter)
- Starter (levain)
- Flour to add
- Water to add
- Salt
- Total dough

## Formula

```
Total flour F (including the flour in the starter) = total dough ÷ (1 + hydration + salt %)
Starter = F × starter %; starter flour = starter ÷ (1 + starter hydration)
Flour to add = F − starter flour; water to add = F × hydration − starter water; salt = F × salt %
```

## Explanation

A typical country loaf uses 75% hydration, 20% starter and 2% salt (all as baker's percentages of total flour). Higher hydration gives a more open crumb but a stickier dough. A 100% hydration starter is equal weights of flour and water.

### How to use the Sourdough Calculator

- **Number of loaves**
- **Dough weight per loaf**
- **Hydration (of total flour)**
- **Starter (% of total flour)**
- **Starter hydration**
- **Salt (% of total flour)**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter the number of loaves, loaf weight, hydration, starter percentage, starter hydration and salt.

### Inputs explained

FieldWhat to enterNumber of loavesA numberDough weight per loafUnits: g, oz, lb, kgHydration (of total flour)In %Starter (% of total flour)In %Starter hydrationIn %Salt (% of total flour)In %

### What each result means

- **Total flour (including starter)** = [Total dough]÷(1 + [Hydration (of total flour)]÷100 + [Salt (% of total flour)]÷100)
- **Starter (levain)** = [Total flour (including starter)]×[Starter (% of total flour)]÷100
- **Flour to add** = [Total flour (including starter)] - [Starter flour]
- **Water to add** = [Total flour (including starter)]×[Hydration (of total flour)]÷100 - ([Starter (levain)] - [Starter flour])
- **Salt** = [Total flour (including starter)]×[Salt (% of total flour)]÷100
- **Total dough** = [Flour to add] + [Water to add] + [Starter (levain)] + [Salt]

### Example values

How the main result changes when **Number of loaves** changes and everything else stays at the example values above:

Number of loavesFlour to add (g)1457.61.5686.42915.32.51,144.131,372.941,830.5

## Worked example

Inputs — Number of loaves: 2; Dough weight per loaf: 900 g; Hydration (of total flour): 75 %; Starter (% of total flour): 20 %; Starter hydration: 100 %; Salt (% of total flour): 2 %.

Results — Total flour (including starter) = 1,016.9 g; Starter (levain) = 203.4 g; **Flour to add = 915.3 g**; Water to add = 661 g; Salt = 20.3 g; Total dough = 1,800 g.

## FAQ

**What is a good sourdough hydration?**
70–80% is typical; beginners may find 65–70% easier to handle.

**How much starter should I use?**
15–25% of the flour weight is common; more starter ferments faster.

**How much salt in sourdough?**
About 2% of the total flour weight.


## Sources

- [King Arthur Baking – Ingredient weight chart](https://www.kingarthurbaking.com/learn/ingredient-weight-chart)