rplc

Calculate the {Multiplier} value for relative constraints in Interface Builder.

This program assumes you have included the following constraints from the Subview to the Superview:

Center Horizontally

Center Vertically

Equal Widths

Equal Heights

Usage:

Quick Calculation: 
  rplc [SuperView Width] [SuperView Height] [View X] [View Y] [View Width] [View Height] 

Multiple Calculations: 
rplc [SuperView Width] [SuperView Height] 
  then:
  [View X] [View Y] [View Width] [View Height] or Press Enter to Exit

iRPLC

The same calculations but on iPhone! Enter all the numbers and you'll see the calculation buttons with Values on them. Click each button to copy to your clipboard, and then use continuity to paste it to the appropriate constraint on your Mac in Xcode.