Natural Logarithm (ln)
The natural logarithm is the logarithm to the base e, where e is an irrational and transcendental constant approximately equal to 2.71828.
ln(x) = loge(x)
Commonly used in calculus and growth/decay models.
Common Logarithm (log)
The common logarithm is the logarithm with base 10. It is also known as the decimal logarithm.
log(x) = log10(x)
Often used in pH levels (acidity), sound intensity (decibels), and Richter scale.
Change of Base Formula
Most calculators only have buttons for ln and log10. To find a logarithm with a different base, use the Change of Base Formula:
logb(x) = ln(x) / ln(b)
This tool uses this method internally to calculate custom bases.