What is a going (tread depth)?
The going (or tread depth) is the horizontal distance of a stair tread — the part on which you place your foot. Together with the rise (the vertical height of each step), the going determines the comfort and safety of a staircase.
How is the going calculated?
The going and rise are linked by a fixed relationship. The commonly used step formula is:
2 × rise + going = 570 to 630 mm
Common dimensions
| Stair type | Going | Rise |
|---|---|---|
| Domestic staircase | 220-250 mm | 170-200 mm |
| Comfortable staircase | 250-300 mm | 150-180 mm |
| Steep staircase (loft) | 150-200 mm | 200-230 mm |
| External staircase | 280-350 mm | 120-160 mm |
Application
The going is important when:
- Designing a staircase — the going determines how much horizontal space the staircase occupies
- Building regulations — minimum going dimensions are specified in building codes
- Safety — a going that is too narrow increases the risk of slipping
- Garden steps — wider treads are used for outdoor stairs for greater comfort
Going vs. tread depth
The going is the clear horizontal distance between the nosings of consecutive treads. Where a nosing (projecting edge) is present, the overall tread depth is slightly larger than the going because the nosing overlaps the tread below.
Tip for DIY builders
When building a staircase: start with the total height (floor-to-floor height) and the available horizontal space. Divide the height by the desired number of steps to determine the rise, then calculate the going using the step formula.
Related terms
- Rise
- Staircase
- Landing
- Nosing
- Building code
Learn more about building terms in our knowledge base at fredsdiyplans.com.