Logarithm calculator
Calculate the logarithm of a number in any base, plus natural log (ln), log10 and log2.
log in base
3
ln (base e)6.907755
log₁₀3
log₂9.965784
The logarithm requires x > 0 and a positive base other than 1.
How the calculation works
A logarithm answers "to what exponent must the base be raised to get x?". For any base, use the change of base: log_b(x) = ln(x) ÷ ln(b).
Frequently asked questions
What is log base 10 of 1000?
3, because 10³ = 1000.
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Updated on June 18, 2026 · by Rafael Rossi · Methodology & sources