# Sourdough Starter Feeding Calculator Calculate feed amounts from retained starter and feeding ratios. [Open this tool](https://whatson.pk/starter-calculator/) Category: Cooking & Baking Retained starter already contains flour and water. A feeding calculation needs that starting composition as well as the fresh feed. Enter the seed amount, hydration and chosen feeding ratio. Compare the fresh flour and water with the resulting total starter. ## Inputs and controls * Retained starter (g). Allowed range: 0.001 to 10000000 * Starter parts (parts). Allowed range: 0.001 to 1000 * Flour parts (parts). Allowed range: 0.001 to 1000 * Water parts (parts). Allowed range: 0 to 1000 * Retained starter hydration (%). Allowed range: 0.1 to 500 ## How to use * Enter retained starter, starter parts, flour parts and water parts. * Enter retained 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 Including the retained seed gives a clearer final hydration figure than calculating only the newly added ingredients. ## Before relying on the result The final hydration includes flour and water already in the seed. Feeding ratios do not predict readiness time or starter health. ## Tool limitations The final hydration includes flour and water already in the seed. Feeding ratios do not predict readiness time or starter health. ## Questions ### Does the ratio tell me when the starter will be ready? No. Temperature and starter condition affect readiness. The result is a feed quantity, not a fermentation timer. ### What should I check before using Sourdough Starter Feeding Calculator? Check Retained starter, Starter parts, Flour parts and Water parts. 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.