Decibel (dB) Reference Levels
The decibel scale is logarithmic — every increase of 10 dB represents a tenfold increase in sound intensity and roughly a doubling of perceived loudness. This reference chart shows common sounds at various dB levels and the maximum safe exposure times defined by health and safety regulations.
Common Sounds & Their dB Levels
| dB SPL | Example sound | Subjective impression |
|---|---|---|
| 0 dB | Threshold of hearing | Absolute silence (lab conditions) |
| 10 dB | Breathing, rustling leaves | Barely audible |
| 20 dB | Whisper at 1 metre | Very quiet |
| 30 dB | Quiet library, soft hum | Quiet |
| 40 dB | Quiet living room, birdsong | Below average ambient |
| 50 dB | Quiet office, rainfall | Comfortable background |
| 60 dB | Normal conversation at 1 m | Moderate |
| 70 dB | Vacuum cleaner, busy traffic | Fairly loud |
| 80 dB | Busy restaurant, alarm clock | Loud — prolonged exposure may cause damage |
| 85 dB | Heavy city traffic, noisy pub | UK workplace action level |
| 90 dB | Lawnmower, food blender | Very loud — hearing protection advised |
| 100 dB | Nightclub, motorcycle at 1 m | Extremely loud |
| 105 dB | Front row at a rock concert | Painful for some people |
| 110 dB | Power tools, car horn at 1 m | Risk of immediate damage |
| 120 dB | Jet engine at 100 m, thunderclap | Threshold of pain |
| 130 dB | Military jet take-off at 15 m | Extremely painful |
| 140 dB | Gunshot, firework at close range | Instant hearing damage possible |
| 150 dB | Jet engine at 25 m | Eardrum rupture risk |
| 194 dB | Theoretical maximum in air | Sound wave becomes a shockwave |
Maximum Safe Exposure Times
The UK Control of Noise at Work Regulations 2005 set a lower exposure action level of 80 dB and an upper level of 85 dB (both as daily or weekly average). For every 3 dB increase above 85 dB, the safe exposure time halves.
| dB level | Max. daily exposure | Example scenario |
|---|---|---|
| 85 dB | 8 hours | Full workday in a noisy factory |
| 88 dB | 4 hours | Extended rehearsal with a band |
| 91 dB | 2 hours | Loud headphone listening |
| 94 dB | 1 hour | Standing near a PA speaker |
| 97 dB | 30 minutes | Nightclub dance floor |
| 100 dB | 15 minutes | Very loud live music |
| 103 dB | 7.5 minutes | Front-of-house at a concert |
| 106 dB | 3.75 minutes | Standing beside a drum kit |
Decibel Calculator
Use our free tool to convert between dB values and calculate combined sound levels:
- Decibel Calculator — add, subtract and convert dB values
dB values are approximate and measured under typical conditions. Actual levels vary with distance, environment and measurement method. Exposure limits are based on the 3 dB exchange rate used in UK and EU regulations.