Natural Log (ln) Calculator
Compute ln(x) and its inverse e^x.
Reviewed by James Whitfield · How we check our maths
Your values
ⓘ Live results
Results
- ln(x)
- 2.995732
- Check: e^ln(x)
- 20
- log10(x)
- 1.30103
Quick answer
The natural logarithm ln(x) is the power to which e (~2.71828) must be raised to produce x.
The formula
ln(x) = log_e(x)
Worked example
Worked example
Using the values the calculator loads with.
Inputs
- Value x20
Result
- ln(x)2.995732
- Check: e^ln(x)20
- log10(x)1.30103
How to use the Natural Log (ln) Calculator
- 1Enter a positive number x.
- 2The natural log uses base e (~2.71828).
- 3The check row confirms e raised to the log returns x.
Frequently asked questions
Can x be zero or negative?
No, the natural log is only defined for positive real numbers.
How is ln related to log base 10?
ln(x) = log10(x) x ln(10), about 2.302585 times log10(x).
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error