Key Stages and year groups explained: UK school ages for international families
A clear map of British school year groups, Key Stages and ages, with how they line up with US grades, for families moving between systems.
British schools organise children by year group and group the years into Key Stages. Once you know the age rule, placing a child is straightforward.
The age rule
The British school year runs from 1 September to 31 August. A child’s year group is set by their age on 31 August:
- A child who is 5 by 31 August starts Year 1 that September.
- Children born in summer (June–August) are the youngest in their year. Those born in September are the oldest.
Most British international schools apply the same rule. Some adjust it to fit the host country’s calendar, so always confirm with the admissions team.
Year groups, Key Stages and ages
| Year group | Age during the year | Key Stage | US grade (approx.) |
|---|---|---|---|
| Nursery (FS1) | 3–4 | EYFS | Pre-K |
| Reception (FS2) | 4–5 | EYFS | Pre-K / K |
| Year 1 | 5–6 | KS1 | Kindergarten |
| Year 2 | 6–7 | KS1 | Grade 1 |
| Year 3 | 7–8 | KS2 | Grade 2 |
| Year 4 | 8–9 | KS2 | Grade 3 |
| Year 5 | 9–10 | KS2 | Grade 4 |
| Year 6 | 10–11 | KS2 | Grade 5 |
| Year 7 | 11–12 | KS3 | Grade 6 |
| Year 8 | 12–13 | KS3 | Grade 7 |
| Year 9 | 13–14 | KS3 | Grade 8 |
| Year 10 | 14–15 | KS4 (GCSE/IGCSE year 1) | Grade 9 |
| Year 11 | 15–16 | KS4 (GCSE/IGCSE exams) | Grade 10 |
| Year 12 | 16–17 | KS5 (Sixth Form) | Grade 11 |
| Year 13 | 17–18 | KS5 (A-Level exams) | Grade 12 |
What happens at each stage
Early Years (EYFS). Learning through play across seven areas, including communication and language, physical development, and personal, social and emotional development. Reception is a structured year that prepares children for formal schooling.
Key Stage 1 (Years 1–2). Phonics-based reading, early writing and number. Children gain independence in the classroom.
Key Stage 2 (Years 3–6). A broader primary curriculum, with growing depth in English, maths and science, plus humanities, arts and often a modern foreign language. Year 6 is the bridge to secondary.
Key Stage 3 (Years 7–9). Specialist subject teachers and a wide curriculum. At the end of Year 9, pupils choose their GCSE or IGCSE options.
Key Stage 4 (Years 10–11). A two-year course leading to around 8–10 GCSEs or IGCSEs. Exams are mostly taken in May and June of Year 11.
Key Stage 5 (Years 12–13). The Sixth Form, usually three or four A-Levels, or the IB Diploma in some schools. This is the stage that leads to university entry.
Placing a child arriving from another system
- From the US: the year group is usually one number above the US grade. A Grade 5 child is normally placed in Year 6. Then check the date of birth against the 31 August rule.
- From the IB: PYP and MYP years line up closely with British year groups, but subject content differs, especially in maths and sciences.
- From local schools: many European systems start formal schooling at 6, so children arriving from them may have had less formal reading instruction than their British peers. Schools usually manage this with targeted support rather than by holding a child back.
Admissions teams sometimes suggest placing a child out of their age group. In British schools this is unusual and can cause problems later, for example with exam entry and university applications, so ask about the long-term implications.
Frequently asked questions
What is the cut-off date for British year groups?
In England, the school year runs from 1 September to 31 August, so a child's year group depends on their age on 31 August. Most British international schools follow the same rule, though some with local calendars adjust it.
What year group is a 10-year-old in?
A child who turned 10 by 31 August will usually be in Year 6, the last year of primary school (Key Stage 2).
Is Year 1 the same as first grade in the US?
Not quite. Year 1 children are generally a year younger than US first graders. Year 2 roughly matches US first grade, and Year 13 matches US Grade 12.