How to calculate gain/attenuation?

[soggybag]

For example, say I have a circuit with a gain of 20. I want to add a voltage divider on the end to bring the gain back down to 1. How do I calculate for this resistor value?

[CynicalMan]

To go from 20 to 1, R2/(R1+R2) = 0.05.

This is a nice tool to find appropriate resistor values:
http://awasteofsalt.com/voltage-divider/

One thing to rememer is that using too small resistor values could load down the preceding circuit too much, and using too large resistor values would make the output impedance too high. Having R1 and R2 total around 100k will work in most cases.

[Gurner]

For example, say I have a circuit with a gain of 20. I want to add a voltage divider on the end to bring the gain back down to 1. How do I calculate for this resistor value?

a simple way is took at this in units....or apples, oranges or whatever!

You have twenty units, you want to be left with one unit....so you need to lose 19 units....... therefore top resistor of 19k & bottom resistor 1k (together they make 20) , or a multiple/division thereof top resistor 38k bottom 2k   or top 9.5k and bottom 500R