# Relation between dB loss and percentage loss

1. Jul 23, 2011

### anarachy

I want to know generally what the relation between dB loss and percentage loss is. If I want to know what percentage of a signals strength is lost knowing what its dB loss is, how would I accomplish that.

Thanks.

2. Jul 23, 2011

### uart

For power loss it would be :

$$100 \left( 1 - 10^{\frac{dB}{10}} \right) \,\%$$

And for voltage loss it would be :

$$100 \left( 1 - 10^{\frac{dB}{20}} \right) \,\%$$

Where dB here would be negative for signal loss.

Last edited: Jul 23, 2011