Log Calculator

Logarithm of a number with any base

Use this when you need a fast, accurate result — no sign-up, works entirely in your browser.

Number (x)

Base

Logarithm—

Check (base^result)—

How to Use

Enter your details into the fields above.
Click the calculate button to get your result instantly.
Use the clear button to start a new calculation.

Example

log₁₀(1000) → 3
ln(1000), base e → 6.9077553

Formula

log_b(x) = ln(x) ÷ ln(b). Common bases: log₁₀ (decimal), log_e = ln (natural), log₂ (binary, used in computing). Only positive x has a real logarithm.

About Log Calculator

Logarithm of a number with any base. This free online tool gives you fast, accurate results without registration or downloads.

Everything runs locally in your browser, so your data is never uploaded or stored — privacy first.

Frequently Asked Questions

Is this tool free to use? +

Yes, it is completely free with no registration or download required.

Is my data private? +

Yes. Everything is processed locally in your browser. Nothing is uploaded or stored on our servers.

Does it work on mobile? +

Yes, it works on any device — phone, tablet, or desktop.