how much is 21 dollars an hour annually?
They essentially mean the same thing just phrased slightly differently. $21 an hour is $43680 annually. This result is found by multiplying $21 x 40 x 52 to get the final annual amount. In the equation the $21 stands for 21 dollars an hour 40 means 40 hours a week and 52 stands for 52 weeks in a year.