Rex says
The fast lane for the math you almost remember from school. Type the numbers, get the answer, move on with your day.
Try a scenario
Click to load — tweak from there.Inputs
Result
Level at new distance (dB)
80.0
Reduction (dB)
20.0
Exposure note
Below 85 dB — safe for 8h
Relative intensity (×)
0.01000
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter level at reference distance (dB).
- 2Enter reference distance (m).
- 3Enter new distance (m).
- 4Read your level at new distance (db) on the right — it updates as you type.
- 5Hit Share to keep the scenario or send it to someone.
About this calculator
Sound pressure falls roughly 6 dB every time distance doubles. Useful for noise complaints, speaker placement, and hearing safety.
Worked example
Using the values the calculator loads with:
Inputs
- Level at reference distance: 100 dB
- Reference distance: 1 m
- New distance: 10 m
Results
- Level at new distance (dB): 80
- Reduction (dB): 20
- Exposure note: Below 85 dB — safe for 8h
- Relative intensity (×): 0.01
What each field means
Inputs
- Level at reference distance (dB)
- The level at reference distance used in the calculation, measured in dB. Starts at 100 dB so you have a working example on load.
- Reference distance (m)
- The reference distance used in the calculation, measured in m. Starts at 1 m so you have a working example on load.
- New distance (m)
- The new distance used in the calculation, measured in m. Starts at 10 m so you have a working example on load.
Results
- Level at new distance (dB)
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Reduction (dB)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Exposure note
- Returned as a plain value. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Relative intensity (×)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the sound level & distance calculator work?
Sound pressure falls roughly 6 dB every time distance doubles. Useful for noise complaints, speaker placement, and hearing safety. The underlying maths is: dB₂ = dB₁ − 20 log₁₀(d₂ ÷ d₁)
What do I need to enter?
3 values: level at reference distance, reference distance, and new distance. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the level at new distance (db) result mean?
It is returned as a decimal number and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Results are rounded for display; the underlying calculation keeps full precision.
Who is this tool for?
It's built for students, developers, and anyone who needs the answer right now without setting up a spreadsheet.
Accuracy and limitations
- Results are rounded for display; the underlying calculation keeps full precision.
- Very large or very small inputs may hit floating-point limits in the browser.
- Inputs outside the accepted range are clamped rather than rejected.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Decibel Distance Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/sound-db
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/sound-db" target="_blank" rel="noopener">Decibel Distance Calculator — RevenueLab</a> (2026).</p>
Source: [Decibel Distance Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/sound-db) (2026).