# RMS to Watts Converter (RMS vs Peak Power)

URL: https://speedycalculator.com/calculators/conversion/rms-to-watts/
Last updated: 2026-10-25

> The RMS to watts converter turns an average (RMS-rated) power into the peak instantaneous power for a sine, square or triangle wave, and back, so you can compare amplifier and speaker ratings.

## Inputs

- RMS (average) power (W, mW, kW)
- Waveform

## Results

- Peak power
- Crest factor

## Formula

```
P_peak = P_RMS × crest factor²   (sine: × 2)
```

## Explanation

“RMS power” on amplifiers really means average continuous power. Peak power is the highest instantaneous power on each cycle; for a pure sine wave it is exactly twice the average. Marketing “peak” or “PMPO” figures can be far larger and are not comparable.

### How to use the RMS to Watts Converter

- **RMS (average) power**
- **Waveform**
- Every result field is editable: type into **Peak power** and **RMS (average) power** plus every other field update to match.

Results update as you type, and every field accepts the units shown in its menu.

### How it works

The average power is multiplied by the square of the waveform’s crest factor (peak voltage ÷ RMS voltage).

### Inputs explained

FieldWhat to enterRMS (average) powerUnits: W, mW, kWWaveformChoose one: Sine wave (crest factor √2), Square wave (crest factor 1), Triangle wave (crest factor √3), Music, typical (crest factor ≈ 4)

### What each result means

- **Peak power** = [RMS (average) power] × [Waveform]
- **Crest factor** = sqrt([Waveform])

### Example values

How the main result changes when **RMS** changes and everything else stays at the example values above:

RMS (average) power (W)Peak power (W)5010075150100200125250150300200400

## Worked example

Inputs — RMS (average) power: 100 W; Waveform: Sine wave (crest factor √2).

Results — **Peak power = 200 W**; Crest factor = 1.414.

## FAQ

**Is RMS power the same as continuous power?**
Yes; it is the average power the amplifier can deliver continuously.

**Why is peak power double the RMS power for a sine wave?**
Peak voltage is √2 × RMS voltage, and power scales with voltage squared.

**What formula does the RMS to Watts Converter use?**
P_peak = P_RMS × crest factor²   (sine: × 2).