Natural Log (ln) Calculator
Compute ln(x) and its inverse e^x.
Enter your values
Enter the value x you are working with.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- 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.
ln(x) = log_e(x)
At a glance
| What it does | Compute ln(x) and its inverse e^x. |
|---|---|
| Category | Math |
| Inputs needed | Value x |
| Main output | ln(x) |
| Formula | ln(x) = log_e(x) |
| Cost | Free — no sign-up, no download |
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.
Inputs explained
- Value x
- Enter the value x you are working with.
Worked example
Using the values the calculator loads with:
Inputs
- Value x20
Results
- ln(x)2.995732
- Check: e^ln(x)20
- log10(x)1.30103
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).
What do I need to enter into the Natural Log (ln) Calculator?
Just 1 value: value x. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Natural Log (ln) Calculator work out the answer?
The natural logarithm ln(x) is the power to which e (~2.71828) must be raised to produce x. It applies the formula ln(x) = log_e(x) and shows the working so you can check each step by hand.
Is the Natural Log (ln) Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.