Plan a staircase from floor-to-floor height
Total rise in, riser count and total run out — plus the stringer length and angle for cutting lumber.
Tools used in this guide
The job
A staircase divides one vertical rise into equal steps. The art is picking a riser count so each step stays climbable — around 7 inches (178 mm), never above the common 7¾-inch (197 mm) residential reference.
Rise + tread
Enter floor-to-floor rise and the tread depth you want; the tool picks the riser count, reports the actual riser height, tread count (risers − 1, since the top step is the landing), total run, stringer length, and angle.
Worked example
A 2,800 mm rise with 280 mm treads lands at 15 risers of ~187 mm — inside the reference, and an angle of ~35.5°. Drop the tread to 250 mm and the same rise runs 3,500 mm horizontally at ~38.7° — steeper, and the flag now trips.
Where it stops
The flag compares against a common reference, not your code — Japan, IRC, and local rules differ (Japan's residential limit is closer to 23 cm riser / 15 cm tread). Straight stairs only: no winders, landings, or headroom math.