Decibel Calculator

Calculate decibels and sound level comparisons.

Sound Level
Normal conversation
Intensity:0.000001 W/m²
Pressure:0.020000 Pa
Common Sound Levels
Threshold of hearing:0 dB
Whisper:20 dB
Normal conversation:60 dB
City traffic:80 dB
Lawn mower:90 dB
Rock concert:110 dB
Threshold of pain:130 dB

How to Do It Manually

Decibels (dB) are logarithmic, measuring sound intensity or power. Increase by 10 dB = 10× power. 20 dB = 100× power.

dB = 10 × log₁₀(intensity / reference intensity) or dB = 20 × log₁₀(amplitude / reference amplitude)
  1. Measure sound pressure or intensity.
  2. Compare to reference (0 dB = threshold of hearing).
  3. Apply the logarithmic formula.

Frequently Asked Questions

Is 60 dB twice as loud as 30 dB?

No, dB is logarithmic. 60 dB is 1,000× more intense than 30 dB.

What's a safe noise level?

Below 85 dB is safe; 85–90 dB for 8 hours is workplace limit; >100 dB causes hearing damage quickly.