Watts to decibels sound power
Type a value in W to get it in dB SWL instantly.
139.5dB SWL
That's 900× as loud as a pneumatic drill, while a jet engine is 35× louder. That is about 90 acoustic watts.
Convert the other way: dB SWL to W
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 W to dB SWL
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 W = 139.542 dB SWL.
Every unit
Your sound power in every unit
Tables
W to dB SWL conversion table
| W | dB SWL |
|---|---|
| 20 W | 133.01 dB SWL |
| 40 W | 136.021 dB SWL |
| 60 W | 137.782 dB SWL |
| 70 W | 138.451 dB SWL |
| 80 W | 139.031 dB SWL |
| 90 W | 139.542 dB SWL |
| 100 W | 140 dB SWL |
| 110 W | 140.414 dB SWL |
| 120 W | 140.792 dB SWL |
| 140 W | 141.461 dB SWL |
dB SWL to W conversion table
| dB SWL | W |
|---|---|
| 20 dB SWL | 1×10⁻¹⁰ W |
| 40 dB SWL | 1×10⁻⁸ W |
| 60 dB SWL | 1×10⁻⁶ W |
| 70 dB SWL | 1×10⁻⁵ W |
| 80 dB SWL | 1×10⁻⁴ W |
| 90 dB SWL | 0.001 W |
| 100 dB SWL | 0.01 W |
| 110 dB SWL | 0.1 W |
| 120 dB SWL | 1 W |
| 140 dB SWL | 100 W |
Quick answers
Quick answers
- How many dB SWL is 1 W?
- 1 W is 120 dB SWL.
- How many dB SWL is 10 W?
- 10 W is 130 dB SWL.
- How many dB SWL is 90 W?
- 90 W is 139.542 dB SWL.
The units
About these units
Watts (W)
The actual acoustic power emitted.
Decibels sound power (dB SWL)
The standard rating, referred to one picowatt.
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