Nearly six hours of class in Costa Rica. Three in Korea.
Welcome to Mapped — one dataset turned into one map, every week. This week: how much of a primary school day is actually class.
A 7-year-old in the OECD gets about 779 hours of compulsory class a year, spread over about 186 school days. That is 4.2 hours of class on a school day. Not the bell-to-bell day, and not lunch or breaks: just the time the timetable calls teaching.
Costa Rica timetables 5.7. Korea timetables 3.1. Same age, almost twice the class.
Remix this map → Opens this exact map in the editor, data included. Change the numbers, the palette, the country. It’s your copy.
What you’re looking at
Each country’s annual hours of compulsory instruction at age 7, divided by its number of primary school days: the average class day, for the school year 2024/25 (a few countries report 2023/24). It covers the OECD countries and partners that publish the figure, not the world — grey means the OECD has no number, not that there’s no school.
The three longest days are all in the Americas. Costa Rica: 1,147 hours over 200 days, about 5.7 hours a day. Chile: 5.4. The United States: 974 hours over 180 days, also 5.4 — and that is class, before lunch and recess are added back. Luxembourg and Portugal are just above five.
The short end: Bulgaria 2.5, Croatia 2.7, Poland, Romania and Latvia 3.0, Korea 3.1, Czechia 3.2. Finland — the country every education debate brings up — teaches its 7-year-olds 3.4 hours a day.
The day and the year are different policies. Israel holds class on 214 days, more than anyone here, and still lands at 4.2 hours a day, right on the OECD average: the year is long, the day is ordinary. Japan has 202 days and a 3.6-hour day, shorter than France’s. Denmark and Costa Rica both run 200 days; Denmark’s day is a full hour shorter.
France is the odd one in the other direction. On paper it averages 4.8 hours over 180 days. In practice primary class is 24 hours a week, and most French primary schools run it over four days with Wednesday off, so the days that exist are closer to six hours. Parents feel the week, not the average.
The short days don’t stay short. Bulgaria and Croatia don’t mean children barely go to school: the early grades are built light. By age 13 a Bulgarian pupil gets 768 hours a year, against 411 at 7. The OECD as a whole goes 779 → 843 → 916 hours at ages 7, 10 and 13.
And more class is not more learning. The OECD’s own note on the school year says instruction time is not closely related to performance. Korea’s official day is among the shortest here, and its 15-year-olds scored 527 in PISA 2022 maths, against an OECD average of 472. Japan scored 536. Costa Rica has the longest day on this map and scored 385.
Korea also shows what this map can’t. It counts the ministry’s timetable, not the family’s. In 2024, 87.7% of Korean primary pupils also took private tutoring. A Korean 7-year-old can leave school at lunchtime and still be in a classroom at dusk — just not one the OECD counts.
The takeaway
Four hours of class is a normal primary day in this club of countries. Five and a half is a policy. Three is also a policy. Neither number ranks the school.
Make this map yourself
The whole map is one maproll URL:
https://api.maproll.io/map.svg?scope=world
&data=CR:5.73,CL:5.44,US:5.41,LU:5.13,PT:5.12,AU:5,...,KR:3.06,PL:3,BG:2.53
&theme=dark&classification=custom&breaks=3.1,3.5,4,4.5,5,6
&legendNoData=No%20OECD%20figure
&legendTitle=class%20hours%20a%20day,%20up%20to
The breaks sit on round half-hours, so a band means something you can say out loud (“under three and a half hours”), and legendNoData labels the grey: a country the OECD has no figure for, not a country with no school. Remix this map → or start from scratch.
Sources: OECD Data Explorer, Education at a Glance instruction-time tables, reference year 2025 (school year 2024/25): compulsory instruction hours per year at age 7, public institutions (DSD_EAG_IT@DF_EAG_IT_AGE), divided by compulsory instruction days in primary education (DSD_EAG_IT@DF_EAG_IT_ORG). The result is an average class day, not a statutory period length, and excludes breaks. The United States, Germany, Brazil and Peru report from the previous school year (2023/24). Belgium is the Flemish and French communities, which both come out at 4.7. England, Scotland and New Zealand don’t set a national hour total the same way, and the Netherlands reports hours but no day count, so all four are grey. Federal countries (United States, Canada, Germany, Australia, Spain) are averages over different state calendars. Instruction-time context: OECD, How is the school year organised in OECD countries?, Education Indicators in Focus No. 86, 2024. PISA 2022 mathematics scores: OECD PISA 2022 Results, Vol. I. Korean private tutoring: Statistics Korea and Ministry of Education, Private Education Expenditures Survey 2024. Next week on Mapped: subscribe below to get it first.