It depends what kind of therapist you want to be. There are so many different schools across the country that offer different programs and it is important to find the right one but typically 2 years after your bachelors.
Traditional DPT programs can range from 30-36 months. So in addition to the 4 years you spend completing an undergraduate degree, you’ll also spend about 3 years at a DPT program, totaling 7 years of college education to become a physical therapist.
This really depends on the type of therapist you would like to be. In addition to the answers above, an occupational therapist program can take between 2-3 years following a bachelor's degree.