Sound Level Converter
Convert between decibels (dB), intensity ratio, and power ratio instantly.
Type in any field and the others update automatically.
Type in any field — the others update instantly. Decibels are logarithmic.
Decibels use a logarithmic scale, not a linear one.
Formulas:
- dB = 10 × log₁₀(power ratio)
- dB = 20 × log₁₀(intensity/amplitude ratio)
- Power ratio = 10^(dB/10)
- Intensity ratio = 10^(dB/20)
Examples:
| dB | Power Ratio | Intensity Ratio |
|---|---|---|
| 0 | 1 | 1 |
| 3 | 2 | 1.41 |
| 6 | 3.98 | 2 |
| 10 | 10 | 3.16 |
| 20 | 100 | 10 |
| 40 | 10,000 | 100 |
| 60 | 1,000,000 | 1,000 |
Common sound levels:
- Whisper: 30 dB
- Normal conversation: 60 dB
- Rock concert: 110 dB
The reason sound uses a logarithmic scale is the sheer range involved: the loudest sound the ear tolerates carries about a trillion times the power of the faintest one it can detect. A linear scale would be unusable, so the decibel compresses that range into manageable numbers.
The catch is that decibels don’t add the way intuition expects. Every 10 dB is a tenfold jump in power, yet the ear hears it as only a rough doubling of loudness. So 70 dB isn’t “a little louder” than 60, it carries ten times the acoustic power. Two identical 60 dB sources together make 63 dB, not 120, because you add power, not the decibel figures. It’s also why hearing damage sneaks up: about 85 dB is the threshold for harm over a long shift, and every 3 dB above that halves the safe exposure time.
How we build and check this converter
This converter runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
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