# Definition:Napierian Logarithm

## Definition

The Napierian logarithms are a system of logarithms where:

$\log_{\text {Nap} } 10 \, 000 \, 000 = 0$
$\log_{\text {Nap} } 9 \, 999 \, 999 = 1$

Thus:

$\log_{\text {Nap} } 10^7 x y = \log_{\text {Nap} } x + \log_{\text{Nap} } y$

## Also defined as

Many sources use the term Napierian logarithm for natural (base $e$) logarithms.

It is wise to make sure of which is meant when referring to them.

## Source of Name

This entry was named for John Napier.