Typescript code for calculating relative coordinates in %

CalculateRelativeCoords.ts

private calculateRelativeCoords(event: MouseEvent): IRelativeCoords {
    const target: JQuery = $(this.target);
    const offset = target.offset();
    const parentOffset = target.offsetParent();

    let relativeX = ((event.pageX - 15) - offset.left);
    let relativeY = ((event.pageY - 15) - offset.top);

    relativeX = (relativeX / target.width()) * 100;
    relativeY = (relativeY / target.height()) * 100;

    relativeX = Math.round(relativeX * 1000) / 1000;
    relativeY = Math.round(relativeY * 1000) / 1000;

    return { relativeX: relativeX, relativeY: relativeY } as IRelativeCoords;
}

export interface IRelativeCoords {
    relativeX: number;
    relativeY: number;
}