For all other iPhone models, in the Settings app, go to Battery and turn on Battery Percentage to see the exact amount of power in the status bar. However, on the iPhone X, X S X S Max and X R this option no longer exists because there is not enough room up there to display the percentage indicator because of the score for the TrueDepth camera system. But that does not mean it's completely gone.
There is no setting that allows you to see the battery percent indicator on your iPhone X. X S X S Max or X R because it is already enabled and hidden in the Control Center area. While you can never look at your iPhone again to see exactly how much battery power is left until it shuts off automatically, you can still make a simple swipe gesture to see it, no matter which screen you're on ,
If you do not yet know how to access the Control Center, just swipe down from the upper right corner of the display where the battery icon and signal strength indicators are located. If you do not want to use the control center, you can simply swipe left to see the percentage, and then quickly boot up without lifting your finger.