Basically, I don't want to waste any RadAway if, for example, it will remove 300 rads and I only have 150. Especially if I'm low on RadAway and/or not near a doctor.
In Fallout 3/New Vegas, I'm used to seeing some number on my Stats page of the pip boy (from what I remember, maybe it was somewhere else exactly). Did Fallout 4 completely remove the exact number and I just have to guess based on my health bar? Or am I missing some other location that will tell me how much I have?