Log Calculator — Base 10, e & Custom
Calculate logarithms in any base
How to Use Logarithm Calculator
Calculate logarithms in any base No signup, and nothing gets uploaded for most use.
- 1
Enter your numbers in the input fields.
- 2
Choose the calculation options or frequency.
- 3
The result updates instantly as you type.
- 4
Review the breakdown, chart, or schedule, and copy the answer.
Why you might like it
- Nothing to upload — the work happens on your device.
- Free with no signup, no watermarks, and no daily limits.
- Works in any modern browser on any device — nothing to install.
- Usually done in a few seconds, so it doesn't get in your way.
Frequently Asked Questions
What is a logarithm?▾
The logarithm log_b(x) answers: to what power must the base b be raised to get x? For example, log₁₀(100) = 2 because 10² = 100. It is the inverse of exponentiation.
What is the change of base formula?▾
It lets you compute a logarithm in any base using another: log_b(x) = ln(x) ÷ ln(b), or equivalently log_b(x) = log₁₀(x) ÷ log₁₀(b). This is how calculators evaluate arbitrary bases.
Related Tools
Percentage Calculator
Calculate percentages, percent change and ratios
Quadratic Equation Solver
Solve quadratic equations with roots and parabola
Scientific Calculator
Full-featured scientific calculator with trigonometry and logs
Cube Root Calculator
Calculate cube roots of any number
Determinant Calculator
Compute determinants and inverses of small matrices
Factorial Calculator
Calculate n! with trailing zeros and digit count
Fraction Calculator
Add, subtract, multiply and divide fractions
GCD Calculator
Find the greatest common divisor with full steps
Learn more
Polynomial: The Complete Guide for 2026
Everything you need to know about polynomial calculator: how it works, key features, and who it helps. Free, private, browser-based — no upload, no signup.
How to Use Polynomial: A Step-by-Step Guide
Learn how to use polynomial calculator in a few simple steps — no install, no signup, no upload. Evaluate polynomials and derivatives at any point.
Polynomial: Formats, File Types, and Size Limits
A practical reference for polynomial calculator: supported input formats, size limits, and how to get the best output. Every file stays on your device.