When are teachers charged for extra hours?
According to the regulations of the Ministry of Education and Training in Circular 21/2025/TT-BGDĐT, overtime teaching salaries (overtime bonuses) are only paid when teachers teach beyond the teaching time limit in the school year.
For general education teachers (from elementary to high school), the quota is determined based on the number of periods/week and the number of actual teaching weeks in the school year (35 weeks), specifically:
Primary school teachers: 23 periods/week × 35 weeks = 805 periods/year;
Secondary school teachers: 19 periods/week × 35 weeks = 665 periods/year;
High school teachers: 17 periods/week × 35 weeks = 595 periods/year.
Thus, only when the total number of actual teaching periods in the school year exceeds the above figures, the exceeding part is counted as overtime teaching.
Circular 21 also stipulates that the total number of extra teaching hours in a school year of each teacher calculated to pay overtime pay is no more than 200 hours.

In case the total number of extra teaching periods in a school year of teachers exceeds 200 periods because the subject cannot arrange enough teachers to teach, the head of the educational institution must notify in writing to the competent authority.
This regulation ensures compliance with the specific characteristics of teachers' professional activities and ensures that teachers do not have to work overtime, have time to rest and regenerate labor, in accordance with the provisions of the Labor Code.
Regular hourly salary of preschool and general education teachers = (Total salary of 12 months in the school year/One-year teaching hours norm) x (22.5 weeks/52 weeks).
One-period teaching salary of university and college lecturers = (Total salary for 12 months/standard teaching hours per year) x (Standard teaching hours per year calculated according to administrative hours/1760 hours) x (44 weeks/52 weeks).
1-period tutoring salary = 1-period regular teaching salary x 150%.
How to calculate overtime for teachers who do not have enough school years
According to Circular 21/2025/TT-BGDĐT, teachers who do not have enough teaching time for one school year are entitled to overtime salaries corresponding to their actual working time.
The salary for 1 teaching period for teachers working for less than one school year is determined as follows:

In which, for teachers in preschool education institutions: Lesson norms/actual working time = (Number of norm teaching hours/day) x (Number of working days/week) x (Number of actual teaching weeks corresponding to actual working time);
For teachers in general education institutions, continuing education institutions, university preparatory schools, specialized schools: Lesson norms/actual working time = (Average lesson norms per week) x (The number of actual teaching weeks corresponds to actual working time);
For teachers of other educational institutions: Lesson norms/actual working time = [(Lesson norms/school year) x (Number of actual teaching weeks corresponding to actual working time)] / (Number of teaching weeks in the school year);
The number of weeks of teaching or teaching children as prescribed does not include the number of preventive weeks.
The total number of extra classes in a school year for teachers as prescribed in this Article is determined as follows:
Number of extra teaching hours of teachers/school year = (Total number of teaching hours in actual working time) - (Level of teaching hours/actual working time).
In which, the total number of teaching periods in actual working time includes: the number of periods taught in actual working time; the number of teaching periods converted in actual working time according to regulations (if any); the number of teaching periods calculated additionally in actual working time according to regulations (if any); the number of teaching periods reduced in actual working time according to regulations (if any); the number of teaching periods included in the number of teaching periods sufficient in actual working time according to regulations (if any).
For teachers assigned to teach on assignment or inter-school, the number of teaching periods in actual working time is the total number of teaching periods in actual working time in all educational institutions where teachers participate in teaching.
Circular 21/2025/TT-BGDĐT has created an important step forward in transparency and standardization of the method of calculating teacher overtime. In addition, the new regulation provides a specific, easy-to-verify formula, ensuring fairness among teachers.