Getting a bar to scale 0-100%

Just a quick one today.

I’ve currently set up my Health bar to use xscale and the health is currently 100 and it all works fine. But I want the hero to be able to upgrade their health to higher values, and when I do this, the bar scales to 120px, 150px, etc, and outside of the Health bars border.

Is there any way to make the bar scale 0-100% relative to the Healths maximum value so values like 200 dont shoot out of the Healthbars border?

Thanks in advance.