math jokes 4 mathy folks
live. laugh. learn.
This form can be used to calculate any of the three terms in a logarithmic expression.

logb a = x    or    bx = a

Enter two of the three values a, b or x, and the third will be calculated.

a (logarithmic number):
b (base):
x (exponent):

decimal places:


Most people think that a logarithm is just a misspelled algorithm.

But logarithms are neat and useful. For instance, the geometric mean of two numbers is equal to the arithmetic mean of the logarithms for those same two numbers. Yeah, that's a mouthful, so here's an example. Notice that…

102 = 100    and    103 = 1000

The geometric mean of 100 and 1000 is 316.228, and the arithmetic mean of 2 and 3 is 2.5. Consequently,

102.5 ≈ 316.228

Pretty cool, huh?