Math · NUMORA
Logarithm Calculator
log base b of x.
Open interactive calculatorHow to use
Change of base: ln x / ln b.
Formula
log_b x = ln x / ln b
FAQ
Is this Logarithm calculator accurate?
The formula and assumptions are shown on the page, and the engine is covered by audit tests. Results are for reference — not financial or medical advice.
Do I need an account?
No. Calculations run in your browser. Recents can stay on this device.
What inputs do I need?
Change of base: ln x / ln b.
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