The decibel (dB) scale measures loudness — but it's not a simple 1-2-3 scale. It's logarithmic, which means the numbers behave very differently from what most people expect.
The scale isn't linear
Every 10 dB increase roughly represents a doubling of perceived loudness, and a 10x increase in actual sound intensity. That's why 70 dB doesn't feel "a bit louder" than 60 dB — it feels roughly twice as loud, because it carries ten times the energy.
Common sound levels
| Sound | Approx. dB |
|---|---|
| Whisper | ~30 dB |
| Quiet room | ~40 dB |
| Normal conversation | ~60 dB |
| Busy traffic | ~80 dB |
| Prolonged exposure risk (OSHA guideline) | ~85 dB |
| Loud concert | ~105 dB |
| Threshold of pain | ~120 dB |
What counts as "safe"?
Occupational safety guidelines (like OSHA in the US) generally flag 85 dB as the point where regular, prolonged exposure starts to risk hearing damage — the louder it gets above that, the shorter the "safe" exposure time. A single loud concert or a power tool for a few minutes isn't the same risk as working an 8-hour shift next to 85+ dB machinery every day; duration matters as much as loudness.
A phone reading is an estimate, not a lab measurement
Every phone and laptop microphone has different sensitivity and built-in processing (noise suppression, automatic gain), so a browser-based sound meter — including this one — gives a useful estimate for comparison, not a certified dB SPL reading. Use it to compare two rooms, check if a space is roughly in the "loud" zone, or get a rough sense of your environment — not for legal or medical measurements, which need calibrated equipment.
Check the noise around you
The free Decibel Meter shows a live, colour-coded reading of the sound around you, right in your browser, with min/max/average tracking for a whole session — nothing is recorded or uploaded.