Riser/tread split, code checks, framing-square settings and a to-scale cut diagram. Single offline HTML file: save it to your phone and it works on site with no signal.
Inputs
Defaults are IRC R311.7 residential limits (max riser 7¾", min tread 10") and a 2×12 stringer (11¼"). Switching units converts the values. Check your local code before cutting.
Results
Checks
Cut diagram (to scale)
Orange = stringer after cutting. The first riser is shortened by the tread thickness ("drop") so every finished step is equal. Dashed line = pitch line through the tooth tips.