I am making a calender of celebrities. Do I have to pay them if I use a photo of them in the calender. If the celebrities are dead do I pay estate?

You absolutely need permission from live persons to use their images in the calendar BEFORE you sell the calendar. They have a right of publicity in the use of their images. The law of the right of publicity is different in each state. However, if you plan on selling the calendar all over the country, you could violate the right of publicity in one or more states. Many states extend the right of publicity to dead persons in which case you need to get permission from their estates.