A good rule of thumb is that tuition rates will increase at about twice the general inflation rate. On average, tuition tends to increase about 8% per year. An 8% college inflation rate means that the cost of college doubles every nine years.
To keep current on tuition inflation, information can be found from industry leaders. Below are reports that have compiled valuable information:
Trends in College Pricing 2021 – CollegeBoard
Tuition Costs of Colleges and Universities – National Center for Education Statistics