API Reference > imodeljs-frontend > QuantityFormatting > QuantityFormatter > setActiveUnitSystem setActiveUnitSystem Method Set the Active unit system to one of the supported types. This will asynchronously load the formatter and parser specs for the activated system. setActiveUnitSystem(isImperialOrUnitSystem: boolean | UnitSystemKey, restartActiveTool?: boolean): Promise<void> Parameter Type Description isImperialOrUnitSystem boolean | UnitSystemKey restartActiveTool boolean Returns - Promise<void> Defined in core/frontend/src/quantity-formatting/QuantityFormatter.ts Line 568 Last Updated: 11 June, 2024