export interface UnitToNumberOptions {
    element?: Element;
    fontSizeFallback?: number;
}
/**
 * A simple util to convert a unit that is using `px`, `em`, or `rem` to a
 * number so that calculations can be made on that unit.
 *
 * @param unit - The unit to convert to a number
 * @param element - The element to use to use for calculating `em`
 * @returns the unit as a number
 */
export declare function unitToNumber(unit: string | number, options?: UnitToNumberOptions): number;