Decibel Calculator for Audio (voltage)

small calculatorIf you don’t like formulas then you definitely won’t like the formula for calculating voltage ratios expressed in decibels.

So, use the following calculators to get a handle on the decibels with different input and outlet levels.

These calculators also show you the theoretical values for resistors to make your own inline audio attenuator, and a calculator to show you the actual dB attenuation with any two real world resistors.

Decibel calculator
Circuit for simple audio attenuator – the value of the resistors are calculated above

For a better understanding of what all this means, read the articles on Understanding Decibels  Part 1 and Part 2.

For those who need to know, the basic formulas used for these calculators are :

\Large{dB = 20 Log_{10}\left(\frac{output\, level}{input\, level}\right)}


\large{Attenuation\ Ratio=\frac{\left(Resistor\,1+Resistor\,2\right)}{Resistor\,1}}


Please Note: During the Covid-19 pandemic I'm busy with a number of streaming projects, and have very limited time to attend to this website. I'm currently taking up to a week to answer questions. Sorry for any inconvenience.

Disclosure: If you buy through this Amazon USA link Geoff receives a small commission from each sale.
European and Australian readers can use the links on the side panel - Thanks for the support

Submit a question or comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.


Thanks very much.nice articles to understand..

Richard (Argentina)

Wonderful Geoff !!!

Charu (Lucknow, India)

wow u r great geoff