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##### AC Voltage Calculator

##### AC Voltage Terms

**Peak Voltage (V**The maximum instantaneous value of a function as measured from the zero-volt level. For the waveform shown above, the peak amplitude and peak value are the same, since the average value of the function is zero volts._{PK})**Peak-to-Peak Voltage (V**The full voltage between positive and negative peaks of the waveform; that is, the sum of the magnitude of the positive and negative peaks._{PP})**RMS Voltage (V**The root-mean-square or effective value of a waveform, equivalent to a DC voltage that would provide the same amount of heat generation in a resistor as the AC voltage would if applied to that same resistor._{rms})**Average Voltage (V**The level of a waveform defined by the condition that the area enclosed by the curve above this level is exactly equal to the area enclosed by the curve below this level._{avg})

##### Notes

- RMS is not an "Average" voltage, and its mathematical relationship to peak voltage varies depending on the type of waveform.
- The RMS value is the square root of the mean (average) value of the squared function of the instantaneous values.
- Since an AC voltage rises and falls with time, it takes more AC voltage to produce a given RMS voltage than it would for DC. For example, it would take 169 volts peak AC to achieve 120 volts RMS (.707 x169).
- Most multi-meters, either voltmeters or ammeters, measure RMS value assuming a pure sinusoidal waveform.

##### AC Voltage Formulas

###### Peak Voltage

- V
_{PK}= 0.5 x V_{PP} - V
_{PK}= 1.414 x V_{rms} - V
_{PK}= 1.571 x V_{avg} ###### Peak-to-Peak Voltage

- V
_{PP}= 2 x V_{PK} - V
_{PP}= 2.828 x V_{rms} - V
_{PP}= 3.141 x V_{avg} ###### RMS Voltage

- V
_{rms}= 0.707 x V_{PK} - V
_{rms}= 0.353 x V_{PP} - V
_{rms}= 1.111 x V_{avg} ###### Average Voltage

- V
_{avg}= 0.637 x V_{PK}