Code Calculator on Webpage

I have a webpage here with a calculator that was designed but, it needs the coding for it to work, currently it's just the design - <[login to view URL]> I need it to work like it does on this other website - <[login to view URL]> Where people can type in their numbers and the calcular will automatically do the calculations. The only difference is for the default numbers you see on the above page, we want ours to be: Appointments per Month: 600 No-Show Rate: 5% Average Loss per Appointment: $70.00 AppointmentRemindMe Success Rate: 80% Cost per Reminder: $.25 This is how the calculator works: All the fields in the top area of the ROI calculator are input by user. In the bottom area it does the calculation based on the numbers the user input. This is the calculation: Monthly Lost Revenue = (Appointments per Month X No-Show Rate) X Average Loss per Appointment. Recovered Revenue = (Appointments per Month X No-Show Rate) X AppointmentRemindMe Success Rate X Average Loss per Appointment. AppointmentRemindMe Investment = (Appointments per Month X Cost Per Reminder) Monthly Return on Investment = Recovered Revenue - AppointmentRemindMe Investment. Our website is coded in html, you will need to have html and php knowledge to do this task. If you bid let me know how much time it will take you to do this, looking for this to be done quickly. Thanks