Decibel Meter for iPhone and Apple Watch
A sound level meter in your pocket. Calibrated dBA readings, records you can keep, video with the level on screen, and your daily noise dose.
Free download · iOS 17.0 or later · Apple Watch
Everything a handheld sound meter does
And a few things it can’t, like filming the noise.
Calibrated for your iPhone
Each iPhone model has its own microphone. The app ships with per-model corrections and lets you fine-tune against a reference meter.
A, C and Z weighting
A for everyday noise and regulations, C for music and machinery, Z for the raw level. Fast and Slow response like a handheld meter.
Min, average, max and peak
The average is a true Leq energy average, the number noise rules are written in. Peak catches the sharpest bang.
Records with charts
Save any session with its full graph, statistics, duration and an optional place name, then open it again later.
Camera mode
Film the source of the noise with the live decibel level on screen. Useful evidence for a noise complaint or a venue check.
Noise dose (OSHA and NIOSH)
See how much of your safe daily exposure a session used, under either the NIOSH or the OSHA rule.
Frequency spectrum
Switch the chart from level-over-time to a live spectrum to see whether the noise is a low hum or a high whine.
Apple Watch
A full meter on your wrist, so you can check a level without taking your phone out.
Export
Share a session as a report or as data to keep with your records or send to a landlord, employer or council.
Show the noise, not just the number
Camera mode puts the live level, minimum, average and maximum on top of the camera picture and records it as a video. A clip of the upstairs neighbour’s speaker at 78 dB at midnight says more than any written complaint.
Every saved session keeps its chart and, if you allow it, the place it was taken, so you can build a log over days or weeks.
Web meter or app?
The free online meter is great for a quick check. The app is for readings you want to trust and keep.
| Online meter | Decibel Meter app | |
|---|---|---|
| Live level in dBA | ✓ | ✓ |
| Min, average (Leq), max | ✓ | ✓ |
| Calibrated per device | – | ✓ |
| C and Z weighting, peak | Z only | ✓ |
| Saved sessions with charts | – | ✓ |
| Video with the level on screen | – | ✓ |
| OSHA / NIOSH noise dose | – | ✓ |
| Works offline, on Apple Watch | – | ✓ |
Questions
Is the Decibel Meter app free?
It is free to download. Measuring and all features are part of Decibel Meter Pro, a subscription you can manage or cancel in your Apple ID settings at any time.
How accurate is a decibel meter app on iPhone?
iPhone microphones are consistent between units of the same model, so a calibrated app is usually within 2–3 dB of a professional meter for everyday levels (roughly 30–100 dBA). It is not a certified Class 1 or Class 2 instrument, so it should not replace one for legal or workplace compliance measurements.
Does it record audio?
No. Measurements are turned into numbers on your phone and the sound itself is discarded. Camera mode records video without an audio track. Nothing is uploaded.
Which iPhones are supported?
Any iPhone running iOS 17.0 or later. The Apple Watch app needs watchOS 10 or later.
More in the user manual and help center (in English).