Grammar School Index

Rochester, Kent · Medway

Sir Joseph Williamson's Mathematical School

Despite its Kent postal address, this school's 11+ has nothing to do with the Kent Test — Medway has run its own separate selection system since becoming a unitary authority in 1998.

Though postally addressed in Kent and popularly called a Kent grammar school, Sir Joseph Williamson's sits in the unitary authority of Medway, which has run its own county-wide '11+' — the Medway Test — since Medway split from Kent County Council administration in 1998. The mechanics differ from the Kent Test in every particular: three separately-weighted papers rather than two, a different annually-recalibrated threshold, and administration by Medway Council rather than KCC. The school's own admissions guidance states directly that the size of a boy's Medway Test score doesn't matter once he's passed — a clean, primary-sourced confirmation that this is not a superselective school.

Key facts

Gender
boys
Age range
11-18
Region
South East
Local authority
Medway
Established
1701
DfE URN
136662
Website
https://sjwms.org.uk

Admissions

Admissions authority
The school sets its own test and criteria
Entrance test board
The Medway Test, commissioned by Medway Council — a separate test system from the Kent Test used elsewhere in the county, run since Medway became a unitary authority in 1998. GL Assessment is reported by tutoring sites as the paper-setter, but not named on Medway Council's own pages.partly verified

GL Assessment is reported by tutoring sites as the Medway Test's provider, but not named on Medway Council's own official pages.

Test format
Three separately-weighted papers, unlike the Kent Test's two: English (comprehension, punctuation, grammar; 30 minutes), Mathematics (50 minutes), and Reasoning (verbal, non-verbal and spatial combined; 45 minutes). English and Maths are each weighted double the Reasoning paper. No separate unmarked writing/appeal task is documented, unlike the Kent Test.
Qualifying / pass mark
The Medway-wide minimum weighted score to be assessed as grammar-suitable, recalibrated annually to target roughly the top 23-26% of the Medway maintained-school cohort: 481 for Sept 2026 entry, 482 for Sept 2025 entry, 492 for Sept 2024 entry. The school applies no higher bar of its own above this county-wide pass mark.sources conflict

Medway Council's own page gives 481/482/492 for 2026/2025/2024 entry. A separate tutoring aggregator states the school's own 'pass mark' as approximately 488 for a similar period — this doesn't match Medway Council's figures and isn't independently sourced; given the school's own statement that the exact score doesn't matter once a pupil has passed, treat 488 as unreliable.

Superselective?
No

Directly stated by the school's own admissions guidance: 'the size of the Medway Test score is not a determining factor. It is just necessary to have passed.' Oversubscription is resolved purely by non-academic criteria — care status, siblings, staff children, then distance — never by ranking on test score. A clean, primary-sourced confirmation rather than a reputational inference.

Catchment & priority criteria

No defined catchment or priority area. After care/sibling/staff-child priority, all remaining places go by distance from home to school (measured via Medway Council's GIS system), with random allocation as the final tie-break.

  1. Looked-after and previously looked-after children
  2. Siblings living in the same household who will be on roll at the time of admission
  3. Children of school staff (specific tenure requirement stated inconsistently across the school's own pages — verify with school)
  4. Distance from home to school, shortest route; ties broken by distance again then random allocation

Results

YearAttainment 8GCSE 5+ Eng & MathsProgress 8A*–AA*–B
202470.16 (school-reported; DfE's own performance-table service blocked automated access throughout this research)97.5%Self-reported by the school as an estimate only, and inconsistently across its own pages: 'above +0.85' in one place, 'in excess of +0.95' in another. This cohort predates the COVID-era gap, so a real DfE figure should exist, but couldn't be independently retrieved.43%73%
A-level: 43% grades A*-A (up from 40% in 2023), 73% grades A*-B.
202569.4993.5%Not calculated — the school's own official performance-data page explicitly states 'N/A for this cohort,' consistent with the nationwide DfE inability to calculate Progress 8 for the 2024/25 GCSE cohort (COVID-cancelled KS2 baseline).44.5%73.7%
The school states official November 2025 DfE performance tables placed it top in Medway on Attainment 8, grade 5+ English & Maths, and EBacc average point score. A-level: 44.5% grades A*-A, 73.7% grades A*-B.

Ofsted

Rating
Outstanding, in every category: quality of education, behaviour and attitudes, personal development, leadership and management, and sixth-form provision.
Date
21-22 March 2023
Report
Read the full report

Sources

  1. 1. DfE Get Information About Schools — URN, status, gender, Medway local authority — https://get-information-schools.service.gov.uk/Establishments/Establishment/Details/136662
  2. 2. School's own Admissions Arrangements 2026-27 — https://sjwms.org.uk/admissions/admissions-arrangements-2026-27/
  3. 3. Medway Council — About the Medway Test — https://www.medway.gov.uk/info/200137/schools_and_learning/1049/medway_test_11
  4. 4. Medway Council — qualifying scores by year — https://www.medway.gov.uk/info/200137/schools_and_learning/1049/medway_test_11/7
  5. 5. Ofsted report, inspected 21-22 March 2023 — https://files.ofsted.gov.uk/v1/file/50217371
  6. 6. School's own history page — founded 1701 — https://sjwms.org.uk/about/history-of-the-school/
  7. 7. School's own Performance & Destinations Data page — https://sjwms.org.uk/about/performance-destinations-data/
  8. 8. School's own A-level Results 2025 page — https://sjwms.org.uk/a-level-results-2025/

Last updated 2026-08-31. Spotted something wrong? Tell us.