Decibel Calculator (Add dB & Distance)
Decibel calculator: add sound levels in dB, find the level at a different distance and compare loudness.
L = 10 · log₁₀ Σ 10Li/10 · L₂ = L₁ − 20 log₁₀(d₂/d₁)
How to use this calculator
- Type your input in the box.
- The result updates as you type.
- Use “Copy result” or “Copy link” to share it.
Decibels add logarithmically: two 80 dB sources make 83 dB, not 160. For a point source the level drops 6 dB each time the distance doubles.
Frequently asked questions
80 + 80 + 75 dB?
About 83.6 dB; at 10× the distance, about 63.6 dB.
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