How to change a value in one box change another too

[deanhystad]

Do exactly what you are doing for the second row. You may have to use some sort of flag to break the cycle.

def factor_changed(self):
    if not self.updating:
        self.updating = True
        self.modified_loss.setText(str(self.factor.value() * self.bat_loss))
        self.updating = False

def modified_loss_changed(self):
    if not self.updating:
        self.updating = True
        self.factor.setText(str(whatever))
        self.updating = False