Decibels sound power to milliwatts
Type a value in dB SWL to get it in mW instantly.
1mW
That's 3.2× as loud as a vacuum cleaner, while a pneumatic drill is 100× louder. That is about 0.001 acoustic watts.
Convert the other way: mW to dB SWL
What it means
How much sound is that?
The one-metre figure assumes a source radiating equally in all directions in free space. Near a wall or a floor the level is higher.
The math
How to convert dB SWL to mW
Sound power level is referred to one picowatt: dB SWL = 10 × log₁₀(W ÷ 10⁻¹²). The pressure level at one metre in free space is 11 dB lower.
Example: 90 dB SWL = 1 mW.
Every unit
Your sound power in every unit
Tables
dB SWL to mW conversion table
| dB SWL | mW |
|---|---|
| 20 dB SWL | 1×10⁻⁷ mW |
| 40 dB SWL | 1×10⁻⁵ mW |
| 60 dB SWL | 0.001 mW |
| 70 dB SWL | 0.01 mW |
| 80 dB SWL | 0.1 mW |
| 90 dB SWL | 1 mW |
| 100 dB SWL | 10 mW |
| 110 dB SWL | 100 mW |
| 120 dB SWL | 1,000 mW |
| 140 dB SWL | 100,000 mW |
mW to dB SWL conversion table
| mW | dB SWL |
|---|---|
| 20 mW | 103.01 dB SWL |
| 40 mW | 106.021 dB SWL |
| 60 mW | 107.782 dB SWL |
| 70 mW | 108.451 dB SWL |
| 80 mW | 109.031 dB SWL |
| 90 mW | 109.542 dB SWL |
| 100 mW | 110 dB SWL |
| 110 mW | 110.414 dB SWL |
| 120 mW | 110.792 dB SWL |
| 140 mW | 111.461 dB SWL |
Quick answers
Quick answers
- How many mW is 1 dB SWL?
- 1 dB SWL is 1.259×10⁻⁹ mW.
- How many mW is 10 dB SWL?
- 10 dB SWL is 1×10⁻⁸ mW.
- How many mW is 90 dB SWL?
- 90 dB SWL is 1 mW.
The units
About these units
Decibels sound power (dB SWL)
The standard rating, referred to one picowatt.
Milliwatts (mW)
For ordinary machines and voices.
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