import type UnitType from './unit-type.js';
import type { ConversionUnitFn } from './types.js';
export interface ConversionByRateOpts {
    unit1?: string;
    unit2?: string;
}
export default function conversionByRate(ut1: UnitType, ut2: UnitType, rate: number | string, opts?: ConversionByRateOpts): ConversionUnitFn;