# Sound Power Level Converter (W / dB Lw re 1 pW)

Convert sound power between linear units (W, mW, µW, pW) and the decibel sound power level dB Lw (Lw = 10·log₁₀(W / 1 pW), reference P₀ = 1 pW = 1e-12 W, per ISO 3744 / IEC 60027-3). Supports bidirectional linear↔logarithmic conversion and reports the equivalent value in all five units. Reference values: whisper ≈ 1e-9 W (Lw ≈ 30), speech ≈ 1e-5 W (Lw ≈ 70), jet engine at 1 m ≈ 1e4 W (Lw ≈ 160).

> Canonical page: https://elysiatools.com/en/tools/sound-power-level-converter

- **Category:** Math & Numbers

- **Keywords:** sound power, sound power level, Lw, decibel, dB, pW, picowatt, SWL, acoustic power, noise emission, ISO 3744, 10 log

## Overview

Convert sound power between W, mW, µW, pW, and dB Lw relative to 1 pW. Enter a value in any supported unit to calculate the equivalent sound power, with results reported across all five units.

## Inputs

- **Input unit** (select)
- **Value** (number): Sound power in the selected Input unit. Must be non-negative (linear) or finite (dB).
- **Output unit** (select)
- **Decimal Places** (number)

## When to use

- Convert a measured or calculated sound power value from watts to dB Lw.
- Convert a dB Lw value back to linear power units such as W, µW, or pW.
- Compare acoustic power values using a consistent reference of 1 pW.

## How it works

- Select the input unit: W, mW, µW, pW, or dB Lw.
- Enter a non-negative linear power value or a finite dB Lw value.
- Choose the preferred output unit and set the number of decimal places from 0 to 10.
- The converter applies Lw = 10·log₁₀(W / 1 pW) or the inverse calculation and reports equivalent values in all five units.

## Use cases

- Acoustic engineering calculations that require sound power and sound power level conversions.
- Noise emission documentation using dB Lw with the 1 pW reference.
- Educational and technical comparisons of values such as whisper-level and speech-level sound power.

## Frequently asked questions

### What reference does dB Lw use?

dB Lw uses a reference sound power of 1 pW, equal to 1e-12 W.

### Can I convert dB Lw to watts?

Yes. Select dB Lw as the input unit and W as the output unit.

### Which input units are supported?

The converter accepts W, mW, µW, pW, and dB Lw.

### What values are valid for linear power?

Linear sound power must be non-negative. dB Lw values must be finite.

### How is the result rounded?

Set Decimal Places to a value from 0 to 10. The default is 6 decimal places.

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