There are a number of websites that provide online calculators intended to help people calculate a correlation coefficient. In fact, there are free online calculators that individuals can easily access. One in particular is easycalculation.com at easycalculation.com/statistics/correlation.php
Another online calculator that you can use is NCalculators, at ncalculators.com/statistics/correlation-coefficient-calculator.htm
Finally, a calculator specific to determining the correlation coefficient is at www.alcula.com/calculators.statistics/correlation-coefficient/
In addition to free online calculators designed to calculate the correlation coefficient, there are websites designed to teach individuals how to do the calculations using step-by-step instructions. See, for example, www.statisticshowto.com/articles/how-to-compute-pearsons-correlation-coefficients/
www.mathisfun.com/data/correlation.html also provides a lesson on how to both understand and calculate the correlation coefficient.
In this age of easy access to online computational programs, there is a risk that students will not actually learn how to solve problems, which is essential for the advancement of society as a whole. The prevalence of calculators, a development largely begun with the introduction of the hand-held models of the 1970s, have fundamentally changed the way students learn math -- for better or for worse.