Turn your browser into a comprehensive noise monitoring tool. Our free online sound level meter measures real-time ambient noise using the dB(A) scale, which accurately reflects human hearing sensitivity. Featuring an integrated noise dosimeter, this webapp doesn’t just track instantaneous sound pressure levels -it calculates your cumulative sound exposure (dose) over time. Perfect for basic workplace safety checks, acoustic analysis, or environmental monitoring.
Turn your phone into a sound level meter: measure ambient noise in dB(A) and find out, with the NIOSH criterion, how long you can be exposed safely. It runs in your browser using the microphone; nothing is recorded or uploaded.
How to read it
The big number is the current level; Leq is the energy average of the whole measurement and Max the loudest peak. The safe time halves for every +3 dB above 85 dB(A). Remember it is indicative (±10 dB) on an uncalibrated mic.
Frequently asked questions
Is a phone sound level meter accurate?
It is indicative, not metrological. Phone microphones are built for voice and are not calibrated, so expect roughly ±10 dB versus a real meter, with the largest errors at very quiet or very loud extremes. Great for "is this around 60 or 90 dB?", not for legal use.
What are dB(A) and Leq?
dB(A) applies a filter that mimics how the ear weights frequencies, so it matches perceived loudness better. Leq is the equivalent continuous level — the energy average over the measurement, a fair summary of fluctuating noise.
How much noise is dangerous?
The NIOSH guideline allows 85 dB(A) for 8 hours, and every +3 dB halves the safe time (88 dB → 4 h, 91 dB → 2 h, 100 dB → 15 min). Below ~80 dB(A) the risk is low. This tool computes that safe time for you.
How do I calibrate it?
Place a trusted sound meter (or one whose reading you know) next to your device in a steady sound and adjust the calibration offset until the numbers match. The offset is saved in your browser.
Indicative measurement on an uncalibrated microphone (±10 dB). Not valid for legal or workplace noise compliance.