Decibel Meter Online – Free Sound Level Meter (Mic)

When to use it

• Get a rough sense of how noisy a room, office or café is
• Watch how loud a neighbor, construction site or appliance seems over time (not for official complaints)
• Check how volume changes while you adjust speakers or headphones
• See whether a nursery or study room is generally quiet

How to use

1. Press Start microphone and allow mic access in your browser.
2. The dBFS value (microphone signal level) and an estimated dB value update in real time.
3. If you own a sound level meter, adjust the calibration offset so both read the same.
4. Check min, average, max and the last-60-seconds graph. Press Reset min/max to start over.

Important: this is not a calibrated instrument

• Phone and computer microphones are not calibrated like a real sound level meter, so readings are estimates.
• The mic type, the operating system's audio processing and phone cases can all change the result.
• Echo cancellation, noise suppression and auto gain are turned off so the raw signal is analyzed.
• For complaints, lawsuits or anything that needs legal evidence, use a certified sound level meter or a professional service.

Typical noise levels (approximate)

• Whisper: about 30 dB
• Quiet library or office: about 40–50 dB
• Normal conversation: about 60 dB
• Vacuum cleaner, street traffic: about 70 dB
• Loud restaurant, subway car: about 80 dB
• Lawn mower, power tools: about 90 dB (risk with long exposure)
• Concert, siren: about 100–120 dB
• Jet takeoff, fireworks: 130 dB or more

NIOSH (US) recommends limiting exposure to an 8-hour average of 85 dBA to reduce the risk of hearing loss.

Tips

• Measure a quiet room first to learn your device's baseline.
• Absolute numbers may be off, but relative changes on the same device and spot are useful.

FAQ