The US 7-11 rule
The 7-11 rule is a widely used shorthand for comfortable residential stair proportions: a riser height around 7 inches (roughly 178mm) paired with a tread going around 11 inches (roughly 280mm). It is a rule of thumb, not a code citation in itself — actual US residential code language (commonly derived from the IRC) usually expresses maximum riser height and minimum tread going as separate numeric limits, and the 7-11 combination happens to sit comfortably inside those limits for most jurisdictions.
| Element | 7-11 rule figure | Typical code limit (confirm locally) |
|---|---|---|
| Riser height | ≈7in / 178mm | Maximum around 7.75in / 196-200mm |
| Tread going (depth) | ≈11in / 280mm | Minimum around 10in / 254mm |
The UK approach: pitch angle plus separate limits
UK Building Regulations (Approved Document K for most dwellings) generally work from a maximum pitch angle for a private stair, often cited as around 42 degrees, combined with its own riser and going limits (commonly riser up to roughly 220mm and going at least roughly 220mm for a private stair, subject to the twice-rise-plus-going relationship also being satisfied). Always check the current edition of the relevant Approved Document or local equivalent, since numeric limits are periodically revised.
| Element | Typical UK private stair guidance (confirm current regs) |
|---|---|
| Maximum pitch | ≈42 degrees |
| Maximum riser | ≈220mm / 8.7in |
| Minimum going | ≈220mm / 8.7in |
| Twice rise + going rule | Often required to fall within roughly 550-700mm / 21.7-27.6in |
Codes change — treat these as starting points
Numeric limits in both US and UK guidance are periodically revised and can vary for public buildings, means of escape, or accessible routes. Confirm the current figures for your jurisdiction and building type before finalising a stair design.
Why the two approaches usually agree in practice
A 7-11 rule stair works out to a pitch of roughly 32-33 degrees, comfortably under the roughly 42-degree UK maximum, and its riser and going figures sit inside typical UK numeric limits too. In other words, a stair built to the American rule of thumb will generally also satisfy UK-style limits, and a stair built to a moderate UK pitch will generally also land near the American comfort rule — the two systems describe overlapping, not conflicting, territory.
Worked comparison
| Riser | Going | Approx. pitch | Fits 7-11 rule? | Fits typical UK limits? |
|---|---|---|---|---|
| 178mm / 7.0in | 280mm / 11.0in | ≈32.4° | Yes (by definition) | Yes |
| 190mm / 7.5in | 250mm / 9.8in | ≈37.2° | Close | Yes, if going ≥ min |
| 200mm / 7.9in | 220mm / 8.7in | ≈42.3° | No — riser high, going shallow | Borderline — check current max pitch |
Know your numbers in 30 seconds
Enter your step count, tread depth and riser height — the stair runner calculator gives you the exact length to order, in metres and feet, with waste included.
Open the stair runner calculatorSteeper stairs: when they're allowed
Both systems permit steeper geometry in specific situations — commonly loft or attic conversions where floor space is limited — sometimes via alternating tread stairs or space-saver designs with their own separate numeric rules rather than the standard private-stair limits. If you are designing to a constrained space, check whether a specific steep-stair or alternating-tread provision applies before assuming the standard limits are your only option.
Common mistakes comparing the two systems
- Treating the 7-11 rule as a legal code citation rather than a rule of thumb that happens to satisfy most codes.
- Applying UK private-stair limits to a public building or escape route, where different numbers usually apply.
- Forgetting the UK twice-rise-plus-going check, which can catch a combination that passes the individual riser and going limits separately.
- Assuming a steep loft-stair exception applies to a main staircase.
- Not rechecking current Approved Document figures, since numeric limits are periodically revised.
Whatever you decide, get the numbers first: the stair runner calculator doubles as a stair runner length calculator, adding nosing wrap, landings, winders, pattern repeat and waste so you order the right length the first time.
Frequently asked questions
What is the 7-11 rule for stairs?
A rule of thumb pairing a roughly 7-inch (178mm) riser with an roughly 11-inch (280mm) tread going, widely used in US residential stair design as a comfortable, code-friendly combination.
What is the maximum stair pitch in the UK?
Commonly cited as around 42 degrees for a private stair under UK Building Regulations, though you should confirm the current Approved Document K figures for your specific project.
Do the US 7-11 rule and UK regulations agree?
They usually overlap in practice — a 7-11 rule stair generally satisfies typical UK numeric limits and pitch maximums too, even though the two systems are expressed differently.
What is the twice-rise-plus-going rule?
A UK check (sometimes written as 2R + G) that riser height doubled, plus tread going, should fall within a set range, commonly cited as roughly 550-700mm, in addition to the individual riser and going limits.
Can stairs be steeper than the standard limits?
Sometimes, for loft or attic stairs with limited space, where alternating tread stairs or space-saver designs are permitted under separate rules — check whether that exception applies before assuming standard limits are mandatory.
Is a comfortable stair pitch always the maximum allowed pitch?
No. The maximum pitch is a legal ceiling, not a comfort target. A pitch well under the maximum, closer to the 7-11 rule's roughly 32-33 degrees, is generally more comfortable for everyday use.
Why do riser and going limits get checked separately from pitch?
Because two very different riser/going combinations can produce the same pitch angle, so codes generally check riser height, going, and sometimes the combined relationship, not pitch alone.
Do these standard figures apply to public buildings?
Not necessarily. Public buildings, means-of-escape stairs and accessible routes commonly have their own, often stricter, numeric limits, separate from private residential stair guidance.
Know your numbers in 30 seconds
Enter your step count, tread depth and riser height — the stair runner calculator gives you the exact length to order, in metres and feet, with waste included.
Check my rise and runEvery guide is written from hands-on measuring and fitting experience, checked against the calculator’s own maths, and re-reviewed whenever prices or methods change. Read our editorial standards.