What it is called, by market
One concept, four markets. Where a name means something else locally, the card says so rather than leaving you to find out on site.
United Kingdom
Same word, different thingrise and going
also riser, tread, total going, pitch line
GOING is the horizontal distance one step advances, measured nosing to nosing; TOTAL GOING is the whole flight. A TREAD is the board you stand on, which is wider than the going by the nosing overlap.
Australia
Close, not identicalrise and going
also riser, tread, going, slope relationship
British terms under Australian standards, with the rise-and-going relationship expressed as a slope range rather than a single formula.
United Statesyours
Same word, different thingrise and run
also riser, tread depth, total run, unit run
RUN means the horizontal advance of one step, but TOTAL RUN means the whole flight and plain run is used for both — so a run figure has to be qualified before it can be used.
Canada
Same word, different thingrise and run
also riser, tread run, total run
As the United States, with the same ambiguity between unit run and total run.
The governing standard, by market
United Kingdom
Approved Document K / BS 5395-1
Protection from falling, collision and impact, including rise and going limits by stair category, and stairs, ladders and walkways.
United States
IRC R311.7 / IBC 1011
Stairway riser height and tread depth limits, the maximum variation between them, and nosing requirements.
Calculators for this
Each works in either measurement system, and the terminology on the page follows whichever market you have selected.
Frequently asked questions
- Is the going the same as the tread?
- No, and the difference is the nosing. The GOING is how far the stair advances per step, measured from the nosing of one tread to the nosing of the next — it is a distance along the stair. The TREAD is the physical board, and where there is a nosing it overhangs the riser below, so the board is wider than the going by that overhang. Order treads to the going and every board is short by the nosing; set out the stair to the tread width and the flight is longer than the space allows. The same trap exists in American usage between unit RUN and TREAD DEPTH, with the additional complication that some codes measure tread depth nosing to nosing anyway — so the word alone never settles it and the drawing has to show where the dimension is taken from.
- Why is there a rule relating rise to going rather than limits on each?
- Because comfort and safety depend on the relationship, not on either dimension alone. A person climbing a stair takes a stride whose length is roughly fixed, and a step that lifts a long way must advance less if the stride is to stay natural — so a tall rise with a deep going is exhausting and a shallow rise with a short going is a trip hazard. Every market encodes that in some form: British guidance gives both individual limits and a combined rule around twice the rise plus the going, and American codes set a maximum riser and a minimum tread which together imply a similar band. The practical consequence is that you cannot fix a stair that is too steep by adjusting only one dimension; both move together, and the total run of the flight moves with them.
- Why does the CONSISTENCY matter as much as the dimension?
- Because people climb stairs without looking at them. After the first two or three steps the body has learned the rhythm and stops watching, so a single step that differs from its neighbours is the one that causes a fall — and the falls it causes are on the way DOWN, with momentum. That is why every code limits the variation between the largest and smallest riser in a flight far more tightly than it limits the riser itself, commonly to a few millimetres across the whole stair. It is also the reason the bottom and top steps are the usual offenders: a floor finish added after the stair was set out changes one riser and nothing else, and a stair that was compliant becomes the most dangerous kind of stair, which is one that looks regular and is not.