A typical US school year is 180 days long, or about 36 weeks of school. Most states set a minimum of around 180 instructional days, though some use a minimum number of hours instead, and the exact rules vary by state and district. Including breaks, the school year usually runs about 40 weeks, from mid-August or early September to late May or June.
The school year in numbers
| Measure | Typical US figure |
|---|---|
| Instructional days | About 180 (commonly 175–186) |
| Weeks of school | About 36 |
| Calendar span, first day to last | About 39–41 weeks |
| Hours per school day | About 6.5–7 |
| Instructional hours per year | About 1,000–1,200 |
| Summer break | About 10–12 weeks |
| Days not in school | About 185 of 365 |
So students are in class on roughly half the days of the year. Over a whole year, 180 days × 6.5 hours is about 1,170 hours, which is only around 20% of a student's waking hours.
How states set the length
- Day requirements: most states require a minimum number of instructional days, with 180 by far the most common figure. A handful set a lower or higher number.
- Hour requirements: some states set a minimum number of instructional hours instead, often different for elementary, middle and high school, which lets districts choose fewer, longer days.
- Four-day weeks: some rural districts, especially in states such as Colorado, Oklahoma and Missouri, run four-day weeks with longer days to meet hour requirements.
- Snow days and make-up days: districts build in buffer days, and many now count remote "e-learning days" toward the total.
Your district's published calendar is the authority for your school's actual dates.
A typical school calendar
| Period | Usual timing | Length |
|---|---|---|
| First day of school | Mid-August (South, Midwest) to after Labor Day (Northeast) | — |
| Fall break / Columbus Day | October | 1–5 days |
| Thanksgiving break | Thanksgiving week | 2–5 days |
| Winter break | Late December to early January | About 2 weeks |
| MLK Day and Presidents' Day | January and February | 1 day each (some districts take a February week) |
| Spring break | March or April | 1 week |
| Memorial Day | Late May | 1 day |
| Last day of school | Late May to late June | — |
Districts in the South and Midwest tend to start and finish earlier; many in the Northeast start after Labor Day and run until late June. Count down with days until back to school, days until Christmas break and days until the last day of school.
Semesters, trimesters and quarters
- Two semesters: about 18 weeks or 90 days each. The most common structure in high schools.
- Four quarters (grading periods): about 9 weeks or 45 days each.
- Three trimesters: about 12 weeks or 60 days each.
How the US compares
US students spend a similar or greater number of hours in school than many other wealthy countries, even though the 180-day year is shorter than in some places. OECD comparisons show that countries differ more in how they spread hours across the year than in the total. Japan and South Korea have school years of around 190–220 days, while many European countries have around 180–190.
Counting down to summer
To work out how many school days are left:
- Count the weekdays between today and the last day of school.
- Subtract holidays, teacher work days and breaks from your district calendar.
- Decide whether to include the last day itself. Most kids do.
The method is the same as for business days. See how to calculate business days. For a fun count, weekends until shows how many weekends remain before a date.
Parents' planning tip: put your district's breaks on the 2027 calendar early. Summer camps and holiday travel fill up months in advance.
Frequently asked questions
How many days are in a school year?
About 180 instructional days in most US states.
How many weeks are in a school year?
About 36 weeks of instruction, spread over roughly 40 calendar weeks including breaks.
How many school days are in a semester?
About 90 days, or 18 weeks.
Which grades are in which school?
See our grades by age chart.