The 2017–18 National Teacher and Principal Survey (NTPS) is a state and nationally representative sample survey of public and private K–12 schools, principals, and teachers in the 50 states and the District of Columbia. The following selected findings are from the Public and Private School Teacher Data Files of the 2017–18 NTPS:

• Race and ethnicity. About 79 percent of all public school teachers were non-Hispanic White, 7 percent were non-Hispanic Black, and 9 percent were Hispanic. Among private school teachers, about 85 percent were non-Hispanic White, 3 percent were non-Hispanic Black, and 7 percent were Hispanic (see table).
• Age. The average age of teachers in traditional public schools was 43 years, and 39 in public charter schools. The average age of teachers in private schools was 44 years old (see table).
• Teaching experience. On average, public and private school teachers had about 14 years of teaching experience. Teachers in traditional public schools had 14 years of teaching experience, and public charter school teachers had 10 years of teaching experience, on average (see table).
• Education level. In the 2017–18 school year, 49 percent of public school teachers had a master’s degree, 39 percent had a bachelor’s degree, 9 percent had higher than a master’s degree, and 3 percent had less than a bachelor’s as their highest degree earned. Among private school teachers, 40 percent had a master’s degree, 42 percent had a bachelor’s degree, 8 percent had higher than a master’s degree, and 10 percent had less than a bachelor’s as their highest degree earned (see table).
• Salary. In the 2017–18 school year regular full-time teachers in public schools had a higher average base salary¹ ($57,900) than regular full-time teachers in private schools ($45,300). About 18 percent of public school teachers and 21 percent of private school teachers had jobs outside their school system during the school year (see table).
• Public school class size.  Among public school teachers in self-contained classrooms, the average class size was 21 students in primary schools, 17 students in middle schools, 16 students for high schools, and 16 students for combined-grade schools. Among departmentalized teachers in public schools, the average class size was 26 for primary schools, 25 for middle schools, 23 for high schools, and 19 for combined-grade schools (see table).
• Private school class size. Among private school teachers in self-contained classrooms, the average class size was 17 students in elementary schools and 18 students in secondary schools. Among departmentalized teachers in private schools, the average class size was 18 for elementary and secondary schools (see table).
• Pre-service coursework. Compared to public school teachers, a lower percentage of private school teachers had taken graduate or undergraduate courses in any of the following subjects prior to their first year of teaching: Lesson planning (79 percent vs. 65 percent), learning assessment (77 percent vs. 65 percent), classroom management techniques (74 percent vs. 62 percent), serving students with special needs (70 percent vs. 49 percent), serving students from diverse economic backgrounds (65 percent vs. 48 percent), using student performance data to inform instruction (56 percent vs. 49 percent), and teaching students who are limited-English proficient or English-language learners (41 percent vs. 28 percent) (see table).
• Evaluation. In the 2017–18 school year, 78 percent of public school teachers and 69 percent of private school teachers were evaluated during the last school year. Among teachers who were evaluated, higher percentages of private school teachers than public school teachers agreed with statements about the positive impact of evaluations on their teaching. Eighty-three percent of private school teachers agreed that the evaluation process helped them determine their success with students, 84 percent agreed that the evaluation process positively affected their teaching, and 81 percent indicated that the evaluation process led to improved student learning. Comparable estimates for public school teachers were 72 percent, 73 percent, and 69 percent respectively (see table).
• Professional development. About 99 percent of all public school teachers reported that they participated in any professional development, and about 94 percent of all private school teachers reported that they participated in any professional development during last school year (see table).

¹ Average base salary is for the school year; summer earnings are not included. Teachers who reported a base salary of zero are excluded.