I was wondering if I take the RMS voltage of a messy looking square wave, a noisy square wave, with some measurement device, and I want to know the regular current of the thing can I take the RMS current and divide it by the square root of 2 in order to get my regular current?

I know you can do this for sinusoidal ac signals but don't know if the math still works out the same for other signals...

PS - I got my RMS current value by dividing the RMS voltage value by a known resistance I have in my circuit

Much Thanks for any responses I get