Calculate: initial fee + monthly recurring fees x amount of clients

When a customer buys a service from my client, they pay an upfront fee then a monthly recurring fee .e.g. $100 upfront fee then $10 every month after that.

I just need a formula that can calculate the totals fee paid after X amount of months.

The variables are:
Amount of upfront fee
Amount of monthly fee
Number of months

A bonus would be if I could have unlimited amount of these calculators on the page so I can have multiple price points for the upfront fee/monthly fee combo.