Logarithm calculator

This calculator works out the logarithm of a number to a given base. The calculator always shows the natural logarithm of the number as well, in the last field. For example, the logarithm

$${\log }_{10}1000$$

means that you are looking for the logarithm of 1,000 to base 10. The logarithm gives you the exponent to which you must raise 10 to get 1,000. So the calculator gives you 3, because 10³ = 1000.