Log and Antilog Calculator

This Log and Antilog calculator makes the log/antilog calculations in which the logarithm of a number to a given base is the power/exponent to which the base must be raised in order to equal that specific no.


Log: *
Base: *
Antilog of: *
Base: *

Other Tools You May Find Useful

■ Factorial Calculator

■ Fraction to Decimal Calculator

■ Decimal to Fraction Calculator

■ Exponent Calculator

What are the log laws and rules?

  • Logarithm formula:

When: b y = a. Results that the base b logarithm of a number a is logb a = y

  • Antilogarithm equation:

When: y = logb a. Results that the antilogarithm (inverse logarithm) is determined by raising the base b to the logarithm y: a = logb-1(y) = b y

  • The product rule of the logarithm:

logb(n ∙ m) = logb(n) + logb(m)

  • The Logarithm quotient rule

logb(n / m) = logb(n) - logb(m)

  • The power rule of the Logarithm

logb(a y) = y ∙ logb(a)

  • Logarithm base change rule

logb(a) = logc(a) / logc(b)

  • Logarithm base switch rule

logb(a) = 1 / loga(b)

How does this log and antilog calculator work?

This calculator has 2 tabs each one designated to perform a specific calculation, as detailed below:

  • The 1st tab can help you calculate the logarithm for a specific number and with a specific base. For example it can find the log10(100000) which is equal to 5 and it will return as well the antilog result which in this case is 105 = 100000.
  • The 2nd tab can be used to discover the antilogarithm for a value and with a specific logarithm base. It finds the Inverse Log values with respect to the base given. For example the antilog of 12 with the e(2.71828183) base is equal to 162754.791419.

15 Apr, 2015