Can I log negative numbers?
Real logarithms only accept positive arguments. The calculator flags invalid inputs if the argument or base is non-positive.
Step-by-step walkthrough
Logarithm Calculator Guide
Use this companion guide beside the interactive calculator to make sure you understand the “why” behind every click. Each section includes the classroom explanation, student-friendly language, and quick practice prompts.
Before you start
Collect the data points listed below and double-check their units. Keeping an organized “givens” list is one of the fastest ways to reduce math errors and impress exam graders.
- logarithm
- log base 10
- natural log
Detailed procedure
Step 1
Enter the argument (a) you want the log of.
Step 2
Select base 10, e, or type a custom base.
Step 3
Read the logarithm value with up to eight decimal places and copy-friendly formatting.
Teaching & troubleshooting tips
Does it show natural logs too?
Yes—the results panel includes both log₁₀ and ln so you can compare values instantly.