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Logarithm Calculator

Calculate logarithms in any base, natural logarithms (ln), log base 2, log base 10, and antilogarithms.

Calculate Logarithm

Calculate logb(x)

Value (x)
Base (b)

Antilogarithm (inverse log)

Exponent (y)
Base
Result
log₁₀(100)
2
10² = 100
LogarithmValue

Logarithm Rules

RuleFormula
Product rulelogb(xy) = logb(x) + logb(y)
Quotient rulelogb(x/y) = logb(x) − logb(y)
Power rulelogb(xⁿ) = n·logb(x)
Change of baselogb(x) = log(x)/log(b) = ln(x)/ln(b)
Inverselogb(bˣ) = x and b^logb(x) = x