Input total rise, desired riser height, tread depth, and nosing the tool instantly calculates step count, actual riser, total run, stringer length, and stair angle in Imperial or Metric units. It includes building code warnings, dark/light theme, and copy, download, email, and print options for easy project sharing.
Math Master tool
Stair Calculator
Unit system
Total rise (vertical height)
Desired riser height (typical 7–8 in / 18–20 cm)
Building code typical: min 4″, max 7.75″ (10–19.7 cm).
Tread depth (horizontal run per step)
Typical minimum 10″ (25.4 cm) for residential.
Nosing overhang (optional)
Typical 0.75–1.25″ (1.9–3.2 cm).