How loud is a rock concert, in decibels?

How to get close to this number

Place it on a scale you already know. Normal conversation sits around sixty decibels, a busy road around eighty, and the threshold where sound becomes physically painful is somewhere near the top of the scale people ever encounter. A concert has to be well above the road and below the pain threshold, which brackets it tightly in the low hundreds.

The decibel scale is the real subject here, and it is where intuition fails. It is logarithmic, so the gap between a vacuum cleaner and a concert is not the modest difference the numbers suggest but the hundredfold difference in energy the explanation describes. Every time you see a decibel figure, remember that adding ten means multiplying the energy by ten — that single rule fixes most misreadings.

The health figure is the part that matters and it is often left out. Damage depends on both level and exposure time, and at concert levels the safe window is measured in minutes, as the explanation says. That is why the figure comes from a public health body rather than an audio one, and why the same loudness is reported differently depending on whether it is measured at the stage, at the desk or in the crowd.