Calculator
Stair builder
Enter the total rise and the run you’ve got to play with. We’ll work out the riser count, riser height and going, and flag anything outside a comfortable range.
Risers6
Riser height166.7 mm
Treads (goings)5
Going (tread depth)480 mm
2R + G comfort813 mm
How this is calculated & assumptions
Riser count is chosen to land the riser height nearest a comfortable ~175 mm. Going = available run ÷ (risers − 1). The “2R + G” value is the classic comfort rule of thumb.
- Comfortable/compliant ranges used here: riser 115–190 mm, going 240–355 mm, 2R + G 550–700 mm. Placeholder — confirm to AS 1657. TBC.
- Amber values fall outside the comfortable range — adjust rise or run.
- Doesn’t account for tread thickness, nosing or landing detail yet.
Stairs off a deck need to be comfortable and compliant. We design and build them as part of a new deck — or read more in the Deckopedia.
Thinking about a new deck — or rescuing an old one?
Tell us about your place. We’ll come out, take a look, and give you a straight answer.