Total rise is the vertical distance from the finished floor level at the bottom of the stairs to the finished floor level at the top of the stairs.

Riser height is the vertical distance from the top of one tread to the top of the next tread. Most codes require this to be fairly consistent, typically between 7 and 7.75 inches.

Tread depth is the horizontal distance from the front edge (nosing) of one tread to the front edge of the next tread above or below it, measured front-to-back. Minimum depth is often 10 inches, excluding nosing.

This is because the top “tread” is often the landing or upper floor itself, so a physical tread piece is not needed there.

Total run is the total horizontal distance the staircase will occupy from the front of the first tread to the back of the last riser before the upper landing.

Stringers are the diagonal structural members that support the treads and risers. They are typically cut from 2×10 or 2×12 lumber.

Common rules (verify locally): Max riser height ~7.75″, min tread depth ~10″, max variation between risers/treads <3/8". Headroom clearance min ~6'8". Railing requirements. This calculator doesn't check all codes.

These are old carpentry guidelines suggesting comfortable stair proportions. Riser + Tread = 17″ to 18″ is one. Another is (2 × Riser Height) + Tread Depth = 24″ to 25″.

Tread nosing is the projection of the tread beyond the riser below it (typically 3/4″ to 1 1/4″). This calculator uses the basic tread depth for run calculation. Nosing adds to the usable surface but not the overall horizontal run of the stringer layout.

Cutting stringers requires precision. Mistakes can be costly. Using a framing square and stringer layout tools is essential. If unsure, consider pre-cut stringers or professional help.