Does your calculator cover my rate of return on my investment. In other words does it consider if I invest the social security money that I receive.

MaximizeMySocialSecurity determines the best filing strategy based on the present value of lifetime benefits. So, the discount rate used to calculate that present value implicitly considers alternate investments. See: https://en.wikipedia.org/wiki/Time_value_of_money, for information on the Time Value of Money. We strongly recommend that you use a discount rate of about 2% to ensure that your are comparing equally risky alternatives.
Best,
Mike