Understanding scaled scores at key stage 1
Source: gov.uk (2025-05-01)

Information for schools and local authorities about scaled scores and the expected standard for the optional key stage 1 national curriculum tests.

Overview

At the end of key stage 1 (KS1), pupils may take part in national curriculum tests in:
- English reading
- English grammar, punctuation and spelling
- mathematics
We use scaled scores to ensure we can make accurate comparisons of pupil performance over time.

Teachers may take a pupil’s performance in the tests into account if they make non-statutory teacher assessment judgements. These judgements can be used to report on the progress of pupils at the end of the key stage.

Scaled score conversion tables

Scaled score conversion tables are available in the collection of national curriculum assessments: past test materials (https://www.gov.uk/government/collections/national-curriculum-assessments-past-test-materials).

What is a scaled score?

Tests are developed to the same specification each year. However, because the questions must be different, the difficulty of tests may vary slightly each year. This means we need to convert the total number of marks a pupil gets in a test (their ‘raw’ score) into a scaled score to ensure we can make accurate comparisons of pupil performance over time.

Pupils scoring at least 100 will always have met the expected standard on the test. However, given that the difficulty of the tests may vary each year, the number of raw score marks needed to achieve a scaled score of 100 may also change. For example, if the overall difficulty of a test decreases compared with previous years, the raw score required to meet the expected standard will increase. Similarly, if the test is more difficult, the raw score required to meet the expected standard will decrease.

In 2016, panels of teachers (https://www.gov.uk/guidance/key-stage-1-tests-standard-setting) set the raw score required to meet the expected standard. We have used data from trialling to maintain that standard for the tests from 2017 onwards.

Calculating raw scores

The optional KS1 tests are marked locally in schools to calculate the total number of marks a pupil receives. Each of the KS1 tests has 2 papers. You add the scores from both papers to calculate the raw score for the test in each subject.

English reading

English grammar, punctuation and spelling

Mathematics

Range of scaled scores and the expected standard

The range of scaled scores available for each test is the same as set in 2016, and is intended to stay the same in future years:

The lowest scaled score that can be awarded on a KS1 test is 85.

The highest scaled score is 115.

Pupils scoring at least 100 will have met the expected standard in the test.

A pupil awarded a score of 99 or less has not met the expected standard in the test.

Pupils need a minimum raw score before they can be awarded the lowest scaled score. Pupils who do not achieve the lowest scaled score on the test have not demonstrated sufficient understanding of the KS1 curriculum in the subject. Where this is the case, schools can:
- award these pupils an ‘N’ for the test in their school’s management information system (MIS)
- assess these pupils using the pre-key stage standards (https://www.gov.uk/government/publications/pre-key-stage-1-standards)
The conversion tables show that sometimes 2 or more raw scores convert to the same scaled score. This is because data from pupils showed that the attainment of pupils who score these total marks is not very different.

There are also times when it is not possible to achieve a particular scaled score on this test. This is because of the limited number of questions in these tests, although these scores may be possible on previous or future tests.

Interpreting test outcomes

The national curriculum tests are compensatory – as pupils can score marks from any parts of the tests, pupils with the same total score may achieve their marks in different ways. The non-statutory KS1 teacher assessment frameworks (https://www.gov.uk/government/publications/teacher-assessment-frameworks-at-the-end-of-key-stage-1) ask teachers to assess pupils against certain aspects of the national curriculum, based on a range of evidence from the classroom. It is possible for a pupil to have met the expected standard in the test but not for teacher assessment, because of gaps in their knowledge or understanding. It is also possible for pupils to have demonstrated their attainment of the ‘pupil can’ statements through their classwork, but not to have achieved the mark for a related question on the test.

Together, the tests and teacher assessment provide a broader picture of pupil attainment.

General enquiries

If you have further questions about national curriculum tests, you can:
- email xxx@xxx.xx (mailto:xxx@xxx.xx)
- call the national curriculum assessments helpline on xx-xxxx-xxxx