Logarithm Calculator

Calculate log base 10, natural log, or any custom base.

Base (b)

x (argument)

Enter your values above and tap Compute log to see the result.

Your Results

log₁₀(x)

ln(x) = logₑ(x)

log₂(x)

Log Rules

log(xy) = log(x) + log(y)
log(x/y) = log(x) − log(y)
log(xⁿ) = n·log(x)
log_b(x) = ln(x)/ln(b)
log_b(b) = 1
log_b(1) = 0
b^(log_b(x)) = x

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Pro Tips

Results update as you type — change any field to see the effect immediately.

Check that every value uses the same unit before comparing results.

Use the copy button to paste the logarithm figures into a note or spreadsheet.

Nothing is sent to a server, so you can use this with private figures.