Tools – ABV Calculator (`/tools/abv`)

Purpose

Help brewers calculate ABV, attenuation, calories, and gravity conversions without leaving the Admin UI.
Persist preferred measurement units so repeated calculations are faster.

Pure client-side utility; no backend fetches. User preferences are stored in cookies (brewski_tools_abv_*).
Uses i18n strings for labels and derives locale-aware number formatting from react-i18next.

Users can toggle between Specific Gravity and Plato scales; converting copies values automatically.
Supports standard vs alternate ABV formulas, updating outputs live as inputs change.
Calorie calculator lets users pick common container volumes with results updated in real time.
Validation guards against invalid ranges (e.g., final gravity higher than original) and surfaces inline alerts when inputs are out of bounds.