Free · in your browser · no recording
Decibel meter online
A free dB meter and noise meter for your phone or computer. Tap Start, allow the mic, and see roughly how loud it is — with a hearing-risk gauge, min / avg / max and a 60-second history.
Sound level · approx. dBIdle
Tap Start and allow microphone access. Nothing is recorded or uploaded.
SessionAvg = Leq
Reading = digital level (dBFS) + 94 dB + your offset. Match it to a known reference meter; the offset is saved on this device.
Approximate, uncalibrated. This is not a certified sound level meter. Phone and laptop microphones vary, and browsers don’t reveal mic sensitivity, so readings can be off by several dB or more. Use it as a guide, not for legal, workplace-compliance or medical decisions.
Reference
How loud is that? Common decibel levels
Typical sound levels at a normal listening distance. Real sources vary a lot with distance — every doubling of distance from a small source drops the level by about 6 dB.
| dB | Sound | Level | Zone |
|---|---|---|---|
| ~10 | Breathing, rustling leaves | Comfortable | |
| ~30 | Whisper | Comfortable | |
| ~40 | Quiet room, library, fridge hum | Comfortable | |
| ~50 | Light rain, quiet office | Comfortable | |
| ~60 | Normal conversation | Comfortable | |
| ~70 | Vacuum cleaner, busy restaurant | Loud | |
| ~80–85 | Busy city traffic (80–85 dB) | Loud | |
| ~90 | Gas lawn mower | Risky over time | |
| ~95 | Motorbike passing | Risky over time | |
| ~105–110 | Rock concert, nightclub (105–110 dB) | Harmful quickly | |
| ~120 | Emergency siren up close | Painful / danger | |
| ~130 | Jet engine nearby — pain threshold | Painful / danger |
Everyday quiet to normal speech.
Noticeably loud. Fine for a while; long days add up.
NIOSH’s 85 dBA / 8 h limit starts here. Time limits shrink fast.
Minutes, not hours. Use hearing protection.
Can hurt and damage hearing in moments.
Want more comparisons? See how loud 50, 60, 70, 80, 90 and 100 dB really are.
Hearing risk
How long is safe? The 85 dB / 3 dB rule
The US National Institute for Occupational Safety and Health (NIOSH) recommends limiting noise exposure to 85 dBA averaged over 8 hours. For every 3 dB louder, the recommended time halves — so 88 dBA is 4 hours and 100 dBA is about 15 minutes.
The World Health Organization’s safe-listening guidance uses a similar idea of a weekly “sound allowance”. Read more in our guide to safe noise levels.
General information only — not medical advice. If you have ringing in the ears or hearing changes, talk to a health professional.
| dBA | Max time per day (NIOSH REL) | Zone |
|---|---|---|
| 85 | 8 hours | Risky over time |
| 88 | 4 hours | Risky over time |
| 91 | 2 hours | Risky over time |
| 94 | 1 hour | Risky over time |
| 97 | 30 minutes | Risky over time |
| 100 | 15 minutes | Harmful quickly |
| 103 | 7.5 minutes | Harmful quickly |
| 106 | about 4 minutes | Harmful quickly |
| 109 | about 2 minutes | Harmful quickly |
| 112 | about 1 minute | Harmful quickly |
| 115 | about 30 seconds | Harmful quickly |
How to
How to measure decibels with this meter
- Tap Start. Press the Start button and allow microphone access when your browser asks. Nothing starts until you tap.
- Hold the device still. Point the microphone (bottom edge on most phones) toward the sound and keep it uncovered, about arm’s length away.
- Read the level. The big number and gauge show the current level in approximate dB. The colour tells you the hearing-risk zone.
- Check min, average and max. Let it run for 30–60 seconds. The history graph and the min / avg / max boxes summarise the session; Reset clears them.
- Calibrate if you can. If you have a known reference (a certified meter or app), adjust the calibration offset until both match. It is saved in this browser.
How the reading is calculated
LoudCheck reads raw microphone samples with the Web Audio API (echo cancellation, noise suppression and auto-gain switched off where the browser allows), calculates the RMS level in dBFS, and adds a fixed +94 dB offset plus your calibration to estimate dB SPL. Readings use energy-based Fast (125 ms) or Slow (1 s) time weighting. Average is the energy average (Leq) of the session.
Values are unweighted and clamped to 0–130 dB. Very quiet rooms may read high because of microphone self-noise; very loud sounds may read low because phone mics compress or clip. For tips by device, see how to measure decibels on a phone.
Coming soon
Get the iOS app
A native LoudCheck app for iPhone is in the works, built for measuring on the go.
- Per-device calibration
- Session logging and export
- Home Screen widget
- Works offline, on-device
Not available yet — no download link. The web meter on this page is free and works today.
Frequently asked questions
Is this online decibel meter accurate?
It gives an approximate reading. Browsers do not expose your microphone’s sensitivity, so LoudCheck converts the digital signal level (dBFS) to an estimated dB SPL with a fixed offset. Expect differences of several dB, sometimes 10 dB or more, depending on the device. Use the calibration offset against a known reference to get closer. It is not a certified sound level meter.
Does the decibel meter record or upload my audio?
No. The sound is analysed in your browser with the Web Audio API and is never recorded, stored or sent anywhere. Only your calibration offset and response setting are saved in your browser’s local storage.
Why does the meter need microphone permission?
A dB meter has to listen to measure loudness. Your browser asks once; if you block it by mistake, re-enable the microphone for this site in your browser’s site settings and tap Start again.
Does it work on iPhone and Android?
Yes. It works in Safari on iPhone and iPad and in Chrome, Edge, Firefox or Samsung Internet on Android, as long as the page is opened over HTTPS and you tap Start. Phone microphones are tuned for voice, so very loud or very low sounds may read less accurately.
What is the difference between dB, dBA and dBFS?
dB SPL is sound pressure level in the air. dBA is SPL with A-weighting, which reduces low and very high frequencies to match human hearing; safety limits such as NIOSH’s 85 dBA use it. dBFS is the digital level relative to the maximum a device can record. This meter measures dBFS and maps it to an approximate, unweighted dB SPL.
How loud is too loud?
As a general guide, NIOSH recommends limiting exposure to 85 dBA averaged over 8 hours, and halving the allowed time for every 3 dB above that — for example about 15 minutes at 100 dBA. This is general information, not medical advice.
What do Fast and Slow response mean?
They set how quickly the reading follows the sound. Fast (about 0.125 s) reacts to short bangs and speech; Slow (about 1 s) smooths the number so it is easier to read in steady noise like traffic or an air conditioner.