Tool Master
Response Weighting:

Analog Decibel Meter

020406080100120140dB SPL
0.0dB

Digital Decibel Display

0.0dB
Minimum
--dB
Average (Leq)
--dB
Peak / Maximum
--dB
Safe Daily Limit
Safe / Unlimited

Microphone Calibration Offset

Add or subtract a constant decibel offset (+/- dB) to calibrate this app against a certified external reference SPL meter for higher precision.

Offset:0.0 dB
-30 dB+30 dB
Raw Sensor0.0 dB+Offset 0.0 dB =Calibrated dB0.0 dB

Real-Time Decibel History (Last 60s)

Audio Frequency Spectrum (FFT)
20 Hz (Bass)1 kHz (Mid)20 kHz (Treble)

Noise Level Reference Guide

Real-time dynamic highlighting matches your current measured ambient noise against standard real-world environmental sound levels.

0–20 dB

Barely Audible

Rustling leaves, calm breathing, recording studio background noise.

20–40 dB

Faint / Very Quiet

Quiet bedroom at night, whisper at 1m, silent library reading room.

40–50 dB

Quiet Environment

Quiet office, gentle rainfall outside, refrigerator humming.

50–60 dB

Moderate / Calm

Quiet residential street, calm conversation, modern dishwasher.

60–70 dB

Normal Conversation

Typical conversation at 1 meter, restaurant murmur, background TV audio.

70–80 dB

Loud Environment

Busy city street traffic, vacuum cleaner, loud alarm clock ringing.

80–90 dB

Very Loud / Hearing Risk

Lawn mower, hair dryer, heavy diesel truck traffic, food blender (Hearing protection recommended).

90–100 dB

Extremely Loud

Motorcycle passing, electric drill, power chainsaw, subway train arrival.

100–110 dB

Critical / Concert Level

Live rock concert, car horn at 1 meter, nightclub audio system, sports stadium.

110–140 dB

Dangerous / Pain Threshold

Emergency siren at close range, jet airplane takeoff at 100m, gunshot, fireworks explosion.

Hearing Health & Safe Daily Exposure Guide

Noise levels at or above 85 dB can cause permanent noise-induced hearing loss (NIHL). Safe exposure times halve for every 3 dB increase (NIOSH standard).

Current LevelSafe Daily LimitStatus / Risk Level
0 – 84.9 dBCurrent Level
Safe / Unlimited Safe & Comfortable
85 – 87.9 dB
Max 8 hours/day Hearing Protection Recommended
88 – 90.9 dB
Max 4 hours/day Hearing Protection Recommended
91 – 93.9 dB
Max 2 hours/day Hazard on Prolonged Exposure
94 – 96.9 dB
Max 1 hour/day Hazard on Prolonged Exposure
97 – 99.9 dB
Max 30 minutes/day Hazard on Prolonged Exposure
100 – 109.9 dB
Max 15 minutes/day Critical Hazard / Acoustic Trauma
110 – 140+ dB
Immediate Hearing Damage Risk Critical Hazard / Acoustic Trauma