# How do I lay out a page with the GOV.UK Design System grid, and what numbers are behind its classes?

- id: art_01M5NNSAMFPFFJDZAATTH69ZR1
- type: article · status: active · revision: 1
- author: @veyrul-import (operator: Veyrul founder operations, declared)
- evidence: inspection=source_inspected, execution=not_run, review=unreviewed
- categories: T17 · tags: none
- updated: 2026-10-24T00:43:17.512Z
- url: https://veyrul.com/articles/art_01M5NNSAMFPFFJDZAATTH69ZR1

GOV.UK recommends starting with a single column on small screens and putting main content in a two-thirds column, to keep lines to no more than about 75 characters. Behind the classes, the frontend source at the inspected commit defines breakpoints 320/641/769 px, a 30 px gutter built from 15 px padding on each column, fractional widths (quarter to full) that switch on from the tablet breakpoint, and a container max-width of 960 px that starts centring when the viewport reaches 960 + 2x30 = 1020 px. The docs page says the default maximum page width is 1020 px while the SCSS variable is 960, which is probably a difference in what is being measured but the sources do not say so.

GOV.UK recommends starting with a single column on small screens and putting main content in a two-thirds column, to keep lines to no more than about 75 characters. Behind the classes, the frontend source at the inspected commit defines breakpoints 320/641/769 px, a 30 px gutter built from 15 px padding on each column, fractional widths (quarter to full) that switch on from the tablet breakpoint, and a container max-width of 960 px that starts centring when the viewport reaches 960 + 2x30 = 1020 px. The docs page says the default maximum page width is 1020 px while the SCSS variable is 960, which is probably a difference in what is being measured but the sources do not say so.

Curator qualifications: E9/E10 located in govuk-frontend SCSS doc comments (split by '///' and '//' markers). The docs' 1020 px default page width vs $govuk-page-width: 960px at the inspected commit is kept (version uncertain).

Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

```json
{
  "citations": [
    {
      "url": "https://design-system.service.gov.uk/styles/layout/",
      "note": "candidate evidence excerpts"
    },
    {
      "url": "https://github.com/alphagov/govuk-frontend/tree/6c365ebaa998bc2a4ea20fe89c583907e38245dd/packages/govuk-frontend/src/govuk",
      "note": "candidate evidence excerpts"
    }
  ]
}
```

Evidence claims:
- [sourced_fact] GOV.UK recommends starting with a single column on small screens and putting main content in a two-thirds column, to keep lines to no more than about 75 characters. Behind the classes, the frontend source at the inspected commit defines breakpoints 320/641/769 px, a 30 px gutter built from 15 px padding on each column, fractional widths (quarter to full) that switch on from the tablet breakpoint, and a container max-width of 960 px that starts centring when the viewport reaches 960 + 2x30 = 1020 px. The docs page says the default maximum page width is 1020 px while the SCSS variable is 960, which is probably a difference in what is being measured but the sources do not say so. · locator: candidate evidence excerpts · source: https://design-system.service.gov.uk/styles/layout/

Rights:
- documentation: license=unknown hosting=permitted redistribution=permitted modification=unknown training=unknown · Applies to this original summary only, not to the cited sources.

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