Sound power converter
Convert sound power between dB SWL and watts, and into the pressure level you would measure a meter away.
That's 3.2× as loud as a vacuum cleaner, while a pneumatic drill is 100× louder. That is about 0.001 acoustic watts.
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.
Every unit
Your sound power in every unit
Learn
Three things worth knowing
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Subtract 11 dB for one meter
A source radiating freely into space gives a pressure level 11 dB below its power level at one meter, and another 6 dB less at every doubling of distance.
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Why the reference is a picowatt
It was chosen so that sound power level and sound pressure level come out as similar numbers for ordinary sources, which makes the arithmetic easier.
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Power and pressure are not the same dB
A vacuum cleaner labelled 80 dB of sound power measures about 69 dB at a metre. Comparing a power rating with a measured level makes the machine look much louder than it is.
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Background
About sound power
Sound power belongs to the machine: it is how much acoustic energy the thing emits, and it does not change with where you stand. Sound pressure is what a microphone measures, and it falls off with distance.
Appliances are labelled in sound power precisely so the rating does not depend on the room.