Base anything

logarithm the base of a logarithm is the number which you are taking powers of. The most common bases used are base 10, since we are fairly familiar with powers of ten, and natural logarithms which are base e, because the number e ≈ 2.718 has important mathematical properties.

In base 10 logarithms, log₁₀ 100 = 2, log₁₀ 1000 = 3, log₁₀ 100000 = 6 etc.