Stair Stringer Calculator

Building stairs and need code-compliant riser and tread dimensions? Get stringer layout with automatic IRC building code validation before you make a single cut.

Stair Stringer Calculator computes riser height, tread depth, stringer length, stair angle, and validates against IRC R311.7 residential stair requirements. Enter your total rise and available run to get a complete stringer layout that passes inspection.

WHAT YOU GET:
- Individual riser height and tread depth
- Number of risers and treads
- Stringer hypotenuse length
- Stair angle from horizontal
- Stock length needed for lumber order

IRC R311.7 CODE CHECKS:
- Maximum riser height 7-3/4 inches (196mm)
- Minimum tread depth 10 inches (254mm)
- Riser uniformity validation
- Headroom clearance check
- Pass/fail status for each requirement

ADJUSTABLE INPUTS:
- Total rise (floor to floor)
- Total run (horizontal distance)
- Number of steps with stepper control
- Instant recalculation on every change

WHO NEEDS THIS:
- Carpenters framing new staircases
- Deck builders planning exterior stairs
- General contractors verifying subcontractor work
- Building inspectors checking compliance

Works completely offline. No account required. Get a code-passing stair layout in seconds before you pick up the saw.