I'm not an experienced instructor, but I suppose it is like running any other business. If you want to profit, you need to figure out what your costs are both direct costs as well as maybe not so obvious overhead costs, and charge enough to cover them plus whatever you need for desired profit and divide by expected number of students to get a per student charge. If this is an all day class, you may need to consider meals or refreshments, or maybe you hold the class at a facility that already covers those things but on their own between the host and your student. Even hotel rooms in some cases may be something to consider, or at least as an available option or informational item to students. You may also consider pre registration and pre payment and at what point do you cancel a class because it is not profitable to go on with it if there are not enough students registered to take the class. (of course it would be a good idea to refund paid fees if you end up canceling) You don't want to spend more on renting a space, and any necessary supplies then you take in because not many people showed up.I'm recently retired and am considering hanging out my own shingle. I've been teaching classes at the local college for 13 years. What do most of you experienced instructors charge for a seminar?