# Sourdough Recipe Calculator

Split total flour and water between a starter and the final mix.

[Open this tool](https://whatson.pk/sourdough-calculator/)

Category: Cooking & Baking

A sourdough formula can be balanced around total flour and total water, with part of each arriving through the starter.

Enter the starter hydration and prefermented flour share, then check what remains for the final mix. Keep starter percentage and flour percentage distinct.

## Inputs and controls

* Total flour including starter (g). Allowed range: 0.001 to 10000000
* Target total hydration (%). Allowed range: 0 to 200
* Flour held in starter (%). Allowed range: 0 to 100
* Salt / total flour (%). Allowed range: 0 to 100
* Starter hydration (%). Allowed range: 0.1 to 500

## How to use

* Enter total flour including starter, target total hydration, flour held in starter and salt / total flour.

* Enter starter hydration.

* Select Calculate result. Read the returned values alongside the assumptions below before copying, exporting or acting on the result.


## Why use this tool

The split lets you weigh the starter and final ingredients without counting the same flour or water twice.


## Before relying on the result

Prefermented flour percentage is not starter mass percentage. A formula that already has too much starter water is rejected.


## Tool limitations

Prefermented flour percentage is not starter mass percentage. A formula that already has too much starter water is rejected.

## Questions

### Why can a requested formula be rejected?

A starter amount may already contribute more water than the target allows. Change the formula rather than treating a negative remaining quantity as an ingredient.

### What should I check before using Sourdough Recipe Calculator?

Check Total flour including starter, Target total hydration, Flour held in starter and Salt / total flour. Use the exact units shown beside the controls and replace any example values with your own inputs.

Source page last modified (UTC): 2026-10-01T16:12:30+00:00

This profile describes the tool. It does not execute it or supply a professional certification.