Decibel Comparison Chart

How to read this table

All examples are approximate: distance, room reflections, duration and weighting change real readings. The decibel scale is logarithmic — 10 dB more means roughly ten times the sound energy. Compare your online decibel meter result only after calibrating your microphone, and match the weighting (usually dBA).

This table is educational context, not medical or regulatory advice. No hearing-safety verdicts are shown on this site because uncalibrated browser readings cannot support them. For protection decisions consult qualified guidance such as CDC/NIOSH and a calibrated meter (accuracy and limitations).

Sources and technical references

Example levels are intentionally approximate. For occupational measurement practice and app limitations, consult CDC/NIOSH Sound Level Meter guidance.

Match your room to the chart in three steps

1. Calibrate with the same A-weighting you plan to compare with, keeping the phone, case and input unchanged.
2. Set the device down and average a full 30 to 60 seconds on Slow response, noting Leq rather than the liveliest peak.
3. Round away decimals and place the Leq beside the nearest chart row. A steady 41 belongs with the quiet-library row; a 66 with voices belongs beside conversation, not beside traffic.

Expect wobble: model spreads of 5 to 10 dB between phones are ordinary, readings below about 30 dBA run high on many handsets, levels near 95 to 100 dBA may clip, and thin bass response understates rumble. Treat the chart as neighbourhood context for a screening check, never as a verdict.

Why the same sofa reads 42 one night and 48 the next

• Moved a half-metre. Corner placement and soft furnishings reshape reflections; measure from the same cushion each time.
• Appliances cycled. A fridge, heater or street gust can lift Leq by 4 to 8 points for a minute, then vanish.
• Hand versus table. Handling and nearby breathing inflate small capsules, so a table reading often drops several points with no change in the room.
• Mixed settings. Swapping A for C or Fast for Slow between nights breaks the comparison. Lock weighting and response first.

Use level plus time before you react

Loudness alone rarely tells the story. Around 85 dBA across 8 hours marks the commonly cited screening boundary, and allowed time roughly halves with every 3 dB increase, while levels under 70 dBA seldom raise duration concern in everyday guidance. A 91 dBA mower patch matters differently from a 91 dBA second-long clatter, so pair any Leq with its duration. Browser figures stay screening-only; formal assessment belongs on purpose-built Class 1 or 2 instruments. To practise that pairing, run the background-noise test and the noise exposure calculator, and read noise exposure and hearing safety.

dB vs dBA → · Open the meter →