Sometimes you want a number for how loud your home or office really is. Without a professional sound level meter, the Decibel Meter can estimate it with your microphone. But there's one thing to understand before you trust the number.
Why the reading is approximate
Decibels (dB) are properly measured with a sound level meter that is calibrated to a known sound pressure. Phone and computer mics aren't built for measurement. They vary from device to device, even within the same model, and the operating system often adjusts or reduces levels automatically (AGC and similar features).
So a browser can only measure the digital signal level the mic receives (dBFS) and add a calibration offset you set to estimate "approximate dB". That's useful for comparing changes, not for absolute accuracy.
When it's still useful
- Comparing whether your home or office is louder than usual
- Watching levels change while you adjust speaker or headphone volume
- Seeing how noise changes over time (day vs night) on the 60-second graph
For noise complaints, disputes or anything that needs official evidence, use a certified sound level meter or ask your local authority or a professional to measure. Readings from an uncalibrated mic are unlikely to be accepted as evidence.
Everyday noise levels (approximate)
These are rough figures that appear across common references. Real levels vary with the situation.
| Sound | Approximate dB |
|---|---|
| Whisper | about 30 dB |
| Quiet library or office | about 40–50 dB |
| Normal conversation | about 60 dB |
| Vacuum cleaner, street traffic | about 70 dB |
| Noisy restaurant, inside a subway car | about 80 dB |
| Lawn mower, power tools | about 90 dB |
| Concert, siren | about 100–120 dB |
| Jet takeoff, fireworks | 130 dB or more |
NIOSH (the US National Institute for Occupational Safety and Health) recommends limiting exposure to an average of 85 dB over 8 hours; regular exposure above that carries a risk of hearing damage. Around 90 dB and above (lawn mowers, power tools), hearing protection such as earplugs is a good idea for long exposure.
Neighbor noise and local rules
In the US, residential noise limits and quiet hours are usually set by your city or county noise ordinance, and they differ from place to place. Look up your local ordinance or contact your city for the actual limits and how they're measured. Official decisions rely on those rules and certified measurements, not a phone reading.
What affects the reading
The same sound in the same room can read differently depending on the distance to the mic, phone cases or screen protectors, the OS's automatic gain control and how each browser handles the mic. The Decibel Meter turns off echo cancellation, noise suppression and auto gain to get as close to the raw signal as possible, but it can't change the device's hardware. Read changes under the same conditions rather than trusting absolute numbers.
How to measure
- Open the Decibel Meter and press Start microphone.
- First measure while it's quiet to get a baseline.
- Measure the sound you're curious about and compare with the baseline.
- Check the 60-second graph to see how it changes over time.
Frequently asked questions
Is a phone decibel meter accurate?
Only approximately. Phone and computer mics aren’t calibrated, so use it to compare changes, not as an exact measurement.
Can I use the reading for a noise complaint?
It’s unlikely to be accepted. Use a certified sound level meter or ask your local authority or a professional to measure.
How loud is too loud?
NIOSH recommends limiting exposure to an average of 85 dB over 8 hours. Use hearing protection for long exposure around 90 dB and above.
What are the noise limits where I live?
In the US they are usually set by your city or county noise ordinance and vary by place. Check your local ordinance.
Sources and date checked
Checked: October 4, 2026
- CDC/NIOSH, Noise and Hearing Loss — https://www.cdc.gov/niosh/noise/about/noise.html
- American Academy of Audiology, Levels of Noise in Decibels (dB) poster — https://www.audiology.org/wp-content/uploads/2023/09/PR23-Poster-NoiseChart-16x20-1.pdf
This article is general information. Limits and figures can change; check current official sources for complaints or legal decisions.