A noise level is how loud a sound is, measured in decibels (dB), usually A-weighted (dBA) to match human hearing. According to NIDCD, sounds at or below 70 dBA are unlikely to cause hearing loss even after long exposure, while long or repeated exposure at or above 85 dBA can cause hearing loss. Start with the decibel meter to measure a room.
- Decibel meterMeasure noise in dBA, dBC or dBZ with average, max, L10/L90, a timeline and CSV.
- Classroom noise meterA full-screen traffic light for the projector, with a quiet-streak timer.
- Noise exposure calculatorYour daily noise dose and 8-hour average under NIOSH and OSHA.
- Decibel chartHow loud common sounds are, with the safe daily time at each level.
- What is a decibel?dB, dBA, dBC and dBFS explained, with a calculator for adding decibels.
Noise levels at a glance
| Level | Example (NIDCD) | Safe daily time (NIOSH) |
|---|---|---|
| 60–70 dBA | Normal conversation | no limit |
| 74–104 dBA | Movie theater | 5 min 57 s at 104 dBA |
| 80–110 dBA | Motorcycles and dirt bikes | 1 min 29 s at 110 dBA |
| 94–110 dBA | Music through headphones at maximum volume, sporting events and concerts | 1 min 29 s at 110 dBA |
| 110–129 dBA | Sirens | 1 s at 129 dBA |
| 140–160 dBA | Fireworks show | less than 1 s at 160 dBA |
Examples from the National Institute on Deafness and Other Communication Disorders (NIH). Times use the NIOSH recommended limit: 85 dBA for 8 hours, halved for every 3 dBA more. The full table with OSHA times is on the decibel chart.
Which tool do I need?
- "How loud is it here?" Use the decibel meter. Read the average (Leq) rather than the jumpy live number.
- "Is my class too noisy?" Use the classroom noise meter on the projector.
- "Is my working day too loud?" Measure each part of the day, then add the periods to the noise exposure calculator.
- "How loud is 85 decibels?" Each level has its own page: 20 to 50 dB · 60 or 70 dB · 75 dB · 80 dB · 85 dB · 90 dB · 100 dB · 110 dB · 120 dB · 150 dB.
- "What do dB and dBA mean?" Read what is a decibel.
A note on phone and laptop microphones
A browser can measure sound only through your device's microphone. Without calibration, readings are an estimate that can be off by 10 dB or more. Treat them as a guide, not as a workplace or legal measurement. NIOSH researchers who tested smartphone sound apps found that external microphones you can calibrate gave much closer agreement with professional meters.
Common questions
What noise level is safe?
NIDCD says sounds at or below 70 dBA are unlikely to cause hearing loss even after long exposure. NIOSH recommends no more than 85 dBA averaged over an 8-hour day.
How do I measure noise levels?
Open the decibel meter on this site, allow the microphone, and let it run for at least a minute in the place you want to measure. Read the Leq (average). Calibrate against a real meter for better accuracy.
What is the difference between dB and dBA?
dB is the plain level. dBA applies the A-weighting curve, which turns down low and very high frequencies the way human hearing does. Hearing limits are set in dBA.
Last reviewed 14 November 2026 by Sri Murugan Systems. Found a mistake? Tell us.