Is this calculation free and private?

Yes, 100% of calculations execute locally in your web browser. No inputs or personal data are stored or transmitted.

What do I need to enter?

Just Sound Pressure Level, Reference Distance and Target Listener Distance. Every field has a sensible default you can start from.

Is my data uploaded anywhere?

No. The calculation runs in your browser with JavaScript — nothing you type is sent to a server or stored.

Does it work on a phone?

Yes. The layout adapts to small screens and needs no app or signup.

Decibel Sound Level & Distance Attenuation Calculator

Calculate sound pressure level (dB SPL) drop over distance using the inverse square law and compare perceived human loudness.

100% free
Private in browser
No signup
No watermarks

Sound Pressure Level (dB SPL)

Reference Distance (Meters)

Target Listener Distance (Meters)

SPL at Target Distance (dB)

76.9

Decibel Drop / Attenuation (dB)

18.1

Perceived Loudness Relative to Ref (x)

0.29

Acoustic Power Drop Factor

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About Decibel Sound Level & Distance Attenuation Calculator

Calculate sound pressure level (dB SPL) drop over distance using the inverse square law and compare perceived human loudness. Enter Sound Pressure Level, Reference Distance and Target Listener Distance and the tool works out SPL at Target Distance, Decibel Drop / Attenuation and Perceived Loudness Relative to Ref straight away. Everything runs in your browser, so your data never leaves your device.

How to use Decibel Sound Level & Distance Attenuation Calculator

Enter Sound Pressure Level, Reference Distance and Target Listener Distance.
Change any value to see the result update instantly.
Read SPL at Target Distance, Decibel Drop / Attenuation and Perceived Loudness Relative to Ref in the results panel — copy or download what you need.

Key features

Shows SPL at Target Distance (dB)
Shows Decibel Drop / Attenuation (dB)
Shows Perceived Loudness Relative to Ref (x)
3 adjustable inputs, results update as you type
No signup, no limits

Frequently asked questions

Is this calculation free and private?: Yes, 100% of calculations execute locally in your web browser. No inputs or personal data are stored or transmitted.
What does the Decibel Sound Level & Distance Attenuation Calculator give me?: It works out SPL at Target Distance, Decibel Drop / Attenuation, Perceived Loudness Relative to Ref and Acoustic Power Drop Factor, updating live as you change the inputs.
What do I need to enter?: Just Sound Pressure Level, Reference Distance and Target Listener Distance. Every field has a sensible default you can start from.
Is my data uploaded anywhere?: No. The calculation runs in your browser with JavaScript — nothing you type is sent to a server or stored.
Does it work on a phone?: Yes. The layout adapts to small screens and needs no app or signup.

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