There are multiple factors that affect visa processing times at the National Visa Center. After completing the initial application, the applicant schedules an interview at their local U.S. Embassy. Wait times for interviews vary from one day to 160 days.
The primary factor is the appointment wait time at the applicant's local U.S. Embassy. The applicant must have all of the required documentation at the time of the interview in order to avoid further delays. Provided the applicant is not flagged for administrative processing, which can delay the process up to 60 days, the applicant's estimated wait time can be found on the U.S. Visa website by entering the applicant's home country.