The RMS or effective value of any AC waveform is an equivalent dc value that provides information about how many volts or amps of DC a time-varying waveform is equal to in terms of its capability to deliver average power.

The effective value of any waveform depends on the type. The most famous example of waveforms around us is the AC waveform at wall outlets in our homes. In most North American countries, the value of the waveform is 120 Vac. The number 120 is the RMS value, implying that the sinusoidal voltage at the wall outlets can deliver the same average power as 120 volts of steady DC.

## Formula for Effective Value of Sine Wave

Given below are a few formulas for calculating effective values of Sine Wave:

I_{eff} = I_{m}/√2 = 0.707 I_{m}

Where

I_{eff} = Effective or RMS value of a current waveform

I_{m} = Peak value of the current waveform

V_{eff} = V_{m}/√2 = 0.707 V_{m}

Where

V_{eff} = Effective or RMS value of voltage waveform

V_{m} = Peak value of voltage waveform

## To calculate peak values from effective values

I_{m} = √2 * I_{eff} = 1.414*I_{eff}

V_{m} = √2 * V_{eff} = 1.414*V_{eff}