Decibels Levels (DBA) and Sones Rating Conversion Chart
While sones and decibels both can be used to measure sound, they focus on different aspects of loudness.
Sone ratings were created to measure how loud we perceive something to be. We hear sound differently based on the frequency, so the higher the frequency, the better we can hear that sound. The sones formula is linear, so 1 sone is precisely half as loud as 2 sones and so on. They are also usually measured in half-sone increments.
Decibel ratings are a more complicated formula. Decibels are used to measure the pressure of sound. Instead of using a linear relationship like sones ratings do, decibels use a logarithmic formula that is a very useful tool for measuring sound. For example, a sound that is 10 times more powerful than 0 dB (near silence) is 10 dB, while a sound that is 100 times more powerful would be 20 dB. Most industrial products, if given a sound rating, will have a decibel rating versus a sones rating.
If you have a sones rating and would prefer a decibel rating, a chart like the one below can be a good tool for understanding the loudness of the equipment you are interested in.
Decibel Level (dBA) Source
1.00 28.00 13.00 64.98 25.00 74.41 37.00 80.06 49.00 84.11
2.00 37.99 14.00 66.05 26.00 74.98 38.00 80.45 50.00 84.41
3.00 43.84 15.00 67.05 27.00 75.52 39.00 80.82 51.00 84.69
4.00 47.99 16.00 67.98 28.00 76.05 40.00 81.19 52.00 84.97
5.00 51.21 17.00 68.85 29.00 76.55 41.00 81.54 53.00 85.25
6.00 53.83 18.00 69.68 30.00 77.04 42.00 81.89 54.00 85.52
7.00 56.06 19.00 70.45 31.00 77.51 43.00 82.23 55.00 85.78
8.00 57.98 20.00 71.19 32.00 77.97 44.00 82.56 56.00 86.04
9.00 59.68 21.00 71.90 33.00 78.41 45.00 82.89 57.00 86.30
10.00 61.20 22.00 72.57 34.00 78.85 46.00 83.20 58.00 86.55
11.00 62.57 23.00 73.21 35.00 79.26 47.00 83.51 59.00 86.79
12.00 63.83 24.00 73.82 36.00 79.67 48.00 83.82 60.00 87.03
FAQs
Is higher or lower sones quieter?
Lower sones will be quieter than higher ratings. Anything under 1 sone will be incredibly difficult to hear.
How are sones and CFM related?
Typically, the sone rating for a fan will increase proportionally with the CFM rating. The higher the CFM rating of the fan, the louder it will be with a higher sone rating.
What does 1.5 sones sound like?
1.5 sones will be extremely quiet, it is comparable to the sound of a refrigerator running.
What does 0.3 sones sound like?
0.3 sones will be as close to silent as possible, and you may not be able to hear the equipment operating at all.