# Convert 'dB per 100m' to 'dB per 1m'

I want to know about wire loss per meter. However, in the datasheet, it is written that 6.1 dB is attenuated per 100 meter, so I wonder if it is possible to simply calculate 0.061 dB if I want to calculate with 1 meter.

If it is possible or impossible, I wonder why?

• Yes it is 0.061 dB/meter. Commented Aug 6, 2021 at 6:31
• dB add linearly. But dB is not a linear scale, of course. It is logarithmic. Commented Aug 6, 2021 at 6:57
• This is thoroughly covered by Wikipedia search Wikipedia decibel
– RoyC
Commented Aug 6, 2021 at 6:59
• I am not questioning whether decibels add linearly because they do; rather, I am questioning if losses in a real world electrical cable add linearly or not, are there extra losses somewhere? I.e. does a 50m cable have less that 3.05 dB loss and 200m cable more than 12.2 dB loss, if a 100m cable has 6.1dB? Commented Aug 6, 2021 at 7:57
• @justme they add linearly. If 100m has 6.1 dB, then it follows that 50m will have 3.1 dB and 200m will have 12.2 dB. Connections will also have losses. Conversions from one type of cable to another, bulkhead fittings, etc. This is called "insertion loss" and would be added to the sum of total cable losses (in dB). Commented Aug 6, 2021 at 8:07