Stair Calculator

Calculate stair dimensions including rise, run, and number of steps. Ensure code compliance for safe, comfortable stairs.

Unit System

Total Rise (in)

Available Run (in)

Desired Tread Depth (in)

Stair Width (in)

Include Railing

Stair Visualization

Code Compliance

Code Compliant

Number of Risers

Number of Treads

Riser Height

7.5″

Tread Depth

10″

Detailed Measurements

Total Run

130″ (10.8 ft)

Stringer Length

167.11″ (13.9 ft)

Headroom Required

80″ (6.7 ft)

Stair Rule (2R + T)

2R + T = 2(7.5) + 10

= 25.00″

Ideal range: 24-25″

Materials Needed

Treads13

Risers14

Stringers3

Railing Length13.93 ft

Balusters84

Stair Basics

Comfortable stairs have consistent risers (vertical) and treads (horizontal). The relationship between them affects comfort and safety. One riser more than treads is standard.

Building Codes

IRC requires max 7.75" rise, min 10" tread depth, and 80" headroom. Check local codes as they may vary. All risers must be uniform within 3/8".

Safety Considerations

The stair rule (2R + T = 24-25") ensures comfortable stride. Handrails are required for 4+ risers. Adequate lighting and non-slip surfaces improve safety.