Indicator D1. How much time do students spend in the classroom?

Both annual instruction time and the length of compulsory education have an impact on the total duration of instruction over the course of compulsory education. In some countries, where compulsory education is shorter, students could face a heavier annual workload to meet the country’s statutory requirements. In other countries the workload is distributed evenly over more years. This indicator focuses on compulsory education at primary and lower secondary levels (in public institutions). However, 25 OECD and partner countries have at least one year of compulsory pre-primary education, so the starting age for compulsory education is younger than the starting age for primary education (see Figure X3.D1.1 in https://doi.org/10.1787/d7f76adc-en (OECD, 2023[2]), for more details on the number of years of compulsory education). Moreover, in around three-fifths of countries and other participants with available data, compulsory full-time education extends into at least one year of upper secondary education (Table D1.1). In most countries a large majority of students remain enrolled after the end of compulsory education (see Indicator B1).

In nearly three-quarters of countries and other participants with available data, students are required to start primary education at the age of 6. In eight other countries and other participants, primary education does not start until children are 7. Only in Australia, England (United Kingdom), New Zealand and Scotland (United Kingdom) does primary education start at age 5 (Table D1.2).

There are also substantial variations in the duration of primary and lower secondary education. On average across OECD countries and other participants, primary education lasts six years, but it ranges from four to seven years. Lower secondary education averages three years, but ranges from two to six years (Table D1.2). The number of grades allocated to each level of compulsory education may also differ within countries, across subnational entities, for example in federal countries such as Canada and the United States (Box D1.2).

Countries and other participants allocate annual instruction time differently over the year. The number of instruction days and the way they are distributed across the school year can vary significantly between countries and other participants, in part because countries organise holidays differently (Box D1.1). The distribution of instruction time during the week also varies. For example, although students go to primary and lower secondary school five days per week in most countries and other participants, students in Belgium and France typically do not attend school on Wednesday afternoon (see Box D1.2 in Education at a Glance 2019 (OECD, 2019[4]). Countries and other participants also differ in the way they organise recesses and breaks within the school day (see Box D1.2 in Education at a Glance 2020 (OECD, 2018[5]).

Intended instruction time is the total number of hours during which schools are obliged to offer instruction in compulsory and, if applicable, non-compulsory subjects. However, intended instruction time could be different from actual instruction time.

In most countries, the total statutory number of hours of intended and/or compulsory instruction time are defined at the national level (i.e. uniform across the country). The total statutory hours of intended and/or compulsory instruction time are defined at the subnational level in some federal countries (e.g. Belgium, Canada, Germany and the United States) and in some countries with a decentralised education system (e.g. Spain and the United Kingdom) (Box D1.2).

Instruction may also occur outside compulsory school hours and outside the classroom or school, but is not covered in this indicator. In some countries, lower secondary school students are encouraged to take after-school classes in subjects already taught in school to help them improve their performance. These lessons might take the form of remedial catch-up classes or enrichment courses, with individual tutors or in group lessons provided by school teachers, or other independent courses (see Box D1.2 in Education at a Glance 2017 (OECD, 2017[6]) and Organisation of the School Day in https://doi.org/10.1787/d7f76adc-en (OECD, 2023[2]), for more information).

Compulsory instruction time refers to the amount of instruction time that almost every public school must provide and almost all public sector students must attend, and how it is allocated, in line with public regulations.

Across OECD countries and other participants, total compulsory instruction time in primary and lower secondary general education averages 7 634 hours spanning across 9 years on average. This ranges from 5 245 hours in Poland (in 8 years) to 11 000 hours in Australia (in 11 years) (Figure D1.1). In England (United Kingdom), New Zealand and Scotland (United Kingdom), the regulations do not prescribe compulsory instruction time in schools. However, schools are required to be open for instruction for a minimum number of hours per day (in New Zealand) or for long enough to deliver a broad and balanced curriculum that meets all statutory requirements (in England and Scotland [United Kingdom]).

On average across OECD countries and other participants, students receive 4 561 hours of compulsory instruction over 6 years of primary education and 3 073 hours during 3 years of lower secondary general education. The average annual number of compulsory instruction hours tend to increase with the level of education in most countries and other participants (from 805 hours in primary education to 916 hours in lower secondary general programmes on average), except in Costa Rica (2% decrease between primary and lower secondary hours), Luxembourg (9% decrease) and Portugal (6% decrease) (Table D1.1.).

Compulsory instruction time per year also generally increases with age on average: 779 hours for 7-year-olds, rising to 846 hours for 10-year-olds and 924 hours for 13-year-olds. In Bulgaria, Croatia, Korea, Latvia, Poland and Romania, average annual compulsory instruction hours increase by more than 40% between the ages of 7 and 13 (Table D1.5, available on line).

Compulsory instruction time, by definition, only captures the time spent by students in formal classroom settings (as established in public regulations). It does not show the actual number of hours of instruction that students receive (for example, adjustment in the organisation of instruction during the COVID-19 pandemic (OECD/UIS/UNESCO/UNICEF/WB, 2021[7]) and nor does it cover learning outside the formal classroom setting.

About three-quarters of countries and other participants with available data have no non-compulsory instruction time, so intended and compulsory instruction time are the same for primary and lower secondary students. In another one-quarter of the countries and other participants (eight countries at primary level and nine at lower secondary level), intended instruction time includes both compulsory instruction time and a specified amount of non-compulsory instruction time (which must be provided in almost every public school, but which is not compulsory for almost all students in public schools). Non-compulsory instruction time might cover various subjects, for example moral and religious education at the primary level in Portugal, or remedial instruction or work on specific projects at the secondary level in Greece (Table D1.1 and https://doi.org/10.1787/d7f76adc-en (OECD, 2023[2]), for more information).

In a few of the countries with available data, non-compulsory instruction time amounts to over 20% of compulsory instruction time. At the primary level, it accounts for 21% of total compulsory instruction time in Slovenia, 25% in Croatia and 52% in Greece. At the lower secondary level, non-compulsory time accounts for 23% of total compulsory instruction time in Slovenia, and 29% in France and Greece (Table D1.3 and Table D1.4). However these values need to be interpreted with caution. In France, for example, there are a wide variety of courses in non-compulsory curriculum at the lower secondary level, and students could not physically attend all the subjects and hours offered.

On average across OECD countries, 41% of compulsory instruction time at primary level is devoted to providing students with fundamental skills in literacy and numeracy: 25% on reading, writing and literature and 16% on mathematics. Croatia, France and Lithuania specifically allocate at least half of compulsory instruction time to reading, writing and literature (first language), and mathematics; Ireland and Luxembourg could also be considered to do the same, as the instruction time devoted to second languages includes other national languages. Together with arts (11%), physical education and health (10%), natural sciences (7%), second and other languages (7%), and social sciences (6%), these seven study areas account for more than 80% of compulsory instruction time on average across OECD countries where instruction time per subject is specified (Table D1.3 and Figure D1.3). The remainder of the non-flexible compulsory curriculum at the primary level is taken up by religion, ethics and moral education; information and communication technologies (ICT); technology; practical and vocational skills; and other subjects, accounting for about 13% of compulsory instruction time on average across OECD countries (Table D1.3).

At lower secondary level, the same seven major study areas at the primary level continue to account for the majority of compulsory curriculum hours (80%), but with a significant shift in the allocation of time within those subjects as the curriculum generally becomes more subject specific. On average across OECD countries where instruction time per subject is specified, reading, writing and literature (15%) and mathematics (13%) make up 27% of the compulsory curriculum; 14 percentage points lower than in primary education. The share of time allocated to physical education and health falls by 2 percentage points (to 8%) and to the arts by 4 percentage points (to 7%) compared to primary education. Conversely, the proportion of compulsory instruction time spent on natural sciences (12%) and social sciences (11%) each rise by 5 percentage points, while the time devoted to second and other languages climbs by 7 percentage points (to 14%). The remaining subjects make up about the same share of the curriculum as they do at primary level (Figure D1.4, Table D1.3 and Table D1.4, and Box D1.3 explores the teaching of vocational subjects in compulsory general education).

At the lower secondary level, there is substantial variation in how countries and other participants allocate time to the different subjects within the compulsory curriculum. For example, reading, writing and literature account for 12% or less of compulsory instruction time in Costa Rica, the Czech Republic, Finland, Ireland, Japan and Sweden, but more than 25% in Greece, Israel and Italy (in Israel and Italy, this also includes time devoted to social sciences). In Ireland, reading, writing and literature are taught in two national languages, with the combined instruction time of the two languages reaching around 17% of the total compulsory instruction time. Natural sciences account for 10% or less of compulsory instruction time in the French Community of Belgium, Iceland, Luxembourg and Norway, but 20% or more in Estonia and Korea (in Korea, this also includes time devoted to ICT, technology, and practical and vocational skills). Compulsory instruction time devoted to second and other languages also varies widely between countries and other participants. Second-language instruction accounts for 7% or less of compulsory instruction time in Costa Rica and Greece and 13% or more in the French Community of Belgium, Iceland, Japan, Latvia and Luxembourg. More than two-fifths of countries with available data allocate some compulsory instruction time to instruction in a further language (Figure D1.4, Table D1.3 and Table D1.4).

As the differences between the primary and lower secondary levels show, there are significant differences in how time is allocated to school subjects as students grow older. For example, on average across OECD countries and other participants, 27% of instruction time is devoted to reading, writing and literature for 7-year-olds, 18% for 11-year-olds, and 12% for 15-year-olds. In contrast, an average of 4% of instruction time for 7-year-olds is devoted to a second language, and this rises to 11% for 11-year-olds (and 1% of time spent studying other languages), while for 15-year-olds, the percentages are 10% for second languages and 5% for other languages. The share of instruction time devoted to other subjects also changes in similar ways across ages (Table D1.6, available on line).

In most countries and other participants, central and state authorities establish regulations or recommendations regarding instruction time and the curriculum. However, local authorities, schools, teachers and/or students also have varying degrees of freedom to organise instruction time or choose subjects.

In more than one-quarter of countries and other participants with available data, the allocation of instruction time across grades is flexible in primary and lower secondary general education. In these countries and other participants, the instruction time for a specific subject is defined for a certain number of grades or even the whole of compulsory education, but the time to be allocated to each grade is not specified. In such cases, schools or local authorities are free to decide how much time should be allocated within each grade (Table D1.2).

Setting compulsory subjects within a flexible timetable is the practice for most subjects in a few countries and other participants. In Portugal, more than half of the compulsory curriculum at the primary level is organised within a flexible timetable, and the proportion exceeds 80% in the Flemish and French Communities of Belgium and in Italy. In the Netherlands and Poland (in each of the first three grades), the entire curriculum at the primary level is organised as a flexible timetable. In Italy, primary schools have autonomy on the allocation of instruction time across subjects in all but a few subjects. The picture is similar at the lower secondary level in the Flemish Community of Belgium and the Netherlands. In these countries and other participants, compulsory subjects and/or total instruction time are specified, but not how time should be allocated to each subject. Local authorities, schools and/or teachers are free to decide how much time to allocate to each compulsory subject. In Scotland (United Kingdom), some compulsory subjects are specified at both primary and lower secondary levels, but total instruction time is the responsibility of local authorities and schools themselves. Excluding these countries and other participants, compulsory subjects with flexible timetables account for only 1% of the compulsory instruction time at both primary and lower secondary levels on average, even if they are a significant part of the curriculum in some countries and other participants (Table D1.3 and Table D1.4).

Flexibility in the choice of subjects is less common across OECD countries and other participants. On average, 3% of compulsory instruction time at the primary level is allocated to subjects chosen by schools. At the lower secondary level, 3% of compulsory instruction time is allocated to subjects chosen by schools and another 3% to subjects chosen by students. However, some countries and other participants allocate a substantial part of the compulsory instruction time to flexible subjects. For example, about 10% or more of compulsory instruction time is allocated to subjects chosen by schools in Chile, the Czech Republic, Estonia (primary), the Flemish Community of Belgium (lower secondary), Israel (primary), the Slovak Republic (lower secondary) and Spain (lower secondary). At least 20% of compulsory instruction time is allocated in this way in Ireland (57% at lower secondary level). In Iceland, Norway and Türkiye, 15-20% of compulsory instruction time is allocated to subjects chosen by lower secondary students (Table D1.3 and Table D1.4).

Compulsory instruction time/curriculum refers to the amount and allocation of instruction time that has to be provided in almost every public school and must be attended by almost all public sector students. The compulsory curriculum may be flexible, as local authorities, schools, teachers and/or students may have varying degrees of freedom to choose the subjects and/or the allocation of compulsory instruction time.

Compulsory flexible subjects chosen by schools refers to the total amount of compulsory instruction time (indicated by the central authorities) which regional authorities, local authorities, schools or teachers allocate to subjects of their choice (or subjects chosen from a list defined by central education authorities). It is compulsory for the school to offer one of these subjects, and students must attend.

Compulsory options chosen by the students refers to the total amount of instruction time in one or more subjects that students have to select (from a set of subjects that are compulsory for schools to offer) in order to cover part of their compulsory instruction time.

Compulsory subjects with a flexible timetable refers to the total amount of instruction time indicated by the central authorities for a given group of subjects which regional authorities, local authorities, schools or teachers allocate to individual subjects. There is flexibility in the time spent on a subject, but not in the subjects to be taught.

Flexible allocation of instruction time across multiple grades refers to the case where the curriculum only indicates the total instruction time for a specific subject for a certain number of grades, or even the whole of compulsory education, without specifying the time to be allocated to each grade. In such cases, schools/local authorities are free to decide how much time should be assigned for each grade.

Instruction time refers to the time a public school is expected to provide instruction to students on all the subjects integrated into the compulsory and non-compulsory curriculum, on school premises or in before-school/after-school activities that are formal parts of the compulsory programme. Instruction time excludes breaks between classes or other types of interruptions, non-compulsory time outside the school day, time dedicated to homework activities, individual tutoring or private study, and examination periods (days for non-school-based examinations, e.g. national examinations).

Intended instruction time refers to the number of hours per year of the compulsory and non-compulsory part of the curriculum that students are entitled to receive in public schools. The intended curriculum can be based on regulations or standards of the central (or top-level) education authorities or may be established as a set of recommendations at the regional level.

The non-compulsory part of the curriculum refers to the total amount of instruction time that public schools must offer on top of the compulsory instruction time, but which is not mandatory for all students. Subjects can vary from school to school or from region to region and take the form of optional subjects. Additional activities before/after classes offered by the school are not per se part of the non-compulsory curriculum; for instance, if there is no obligation upon public schools to provide this instruction time or it is not part of the official curricula. In particular, non-compulsory education excludes morning or after-school care classes, even if they are officially regulated.

This indicator captures intended instruction time (as established in public regulations) as a measure of learning in formal classroom settings. It does not show the actual number of hours of instruction that students receive and does not cover learning outside of the formal classroom setting. Differences may exist across countries and other participants between the regulatory minimum hours of instruction and the actual hours of instruction received by students. Given such factors as school timetables, lesson cancellations and teacher absenteeism, schools may not consistently attain the regulatory minimum instruction time (see Box D1.1 in Education at a Glance 2007 (OECD, 2007[8])).

This indicator also illustrates how minimum (and/or recommended) instruction hours are allocated across different curricular areas. It shows the intended net hours of instruction for those grades that are part of compulsory full-time general education. Although the data are difficult to compare among countries and other participants because of different curricular policies, they nevertheless provide an indication of how much formal instruction time is considered necessary for students to achieve the desired educational goals.

When the allocation of instruction time across grades is flexible (i.e. instruction time for a specific subject is defined for a certain number of grades, or even the whole of compulsory education, without specifying the time to be allocated to each grade), instruction time per age or level of education was estimated by assuming equal distribution of the total number of instruction hours between grades.

For more information please see the https://doi.org/10.1787/9789264304444-en (OECD, 2018[9]) and https://doi.org/10.1787/d7f76adc-en (OECD, 2023[2]).

Data on instruction time are from the 2022 Joint Eurydice-OECD Instruction Time data collection and refer to instruction time during compulsory primary and full-time (lower and upper) secondary general education for the school year 2022/23. Data on school calendars are from the 2022 Joint Eurydice-OECD data collection on school calendars and refer to dates on holiday periods for students at primary and (lower and upper) secondary education for the school year 2022/23.

References

[2] OECD (2023), Education at a Glance 2023 Sources, Methodologies and Technical Notes, OECD Publishing, Paris, https://doi.org/10.1787/d7f76adc-en.

[3] OECD (2021), Education at a Glance 2021: OECD Indicators, OECD Publishing, Paris, https://doi.org/10.1787/b35a14e5-en.

[1] OECD (2021), The State of Global Education: 18 Months into the Pandemic, OECD Publishing, Paris, https://doi.org/10.1787/1a23bb23-en.

[4] OECD (2019), Education at a Glance 2019: OECD Indicators, OECD Publishing, Paris, https://doi.org/10.1787/f8d7880d-en.

[5] OECD (2018), Education at a Glance 2018: OECD Indicators, OECD Publishing, Paris, https://doi.org/10.1787/eag-2018-en.

[9] OECD (2018), OECD Handbook for Internationally Comparative Education Statistics 2018: Concepts, Standards, Definitions and Classifications, OECD Publishing, Paris, https://doi.org/10.1787/9789264304444-en.

[6] OECD (2017), Education at a Glance 2017: OECD Indicators, OECD Publishing, Paris, https://doi.org/10.1787/eag-2017-en.

[8] OECD (2007), Education at a Glance 2007: OECD Indicators, OECD Publishing, Paris, https://doi.org/10.1787/eag-2007-en.

[7] OECD/UIS/UNESCO/UNICEF/WB (2021), OECD/UIS/UNESCO/UNICEF/WB Special Survey on COVID, http://oecd.org/education/state-of-school-education-one-year-into-COVID.htm (accessed on 13 April 2021).

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