What Is the L-Shaped Calculator?
Design L-shaped stairs with a 90-degree turn and intermediate landing using our free calculator. L-shaped staircases are among the most popular residential stair configurations because they break up a long flight, provide a resting point, and fit well into corner floor plans.
How to Use This Calculator
- Enter the total rise and your target riser height.
- Specify the tread depth and stair width.
- Set the landing depth - must be at least equal to the stair width per code.
- Review both flights and the overall footprint dimensions.
Why Accurate L-Shaped Calculations Matter
L-shaped stairs offer better safety than straight stairs because the landing breaks a potential fall path. The IRC requires landings to be at least as deep as the stair width, and the landing must be level with no more than a ¼-inch slope per foot for drainage.
Building Code References
Related Tools
Frequently Asked Questions
What is the minimum landing size for L-shaped stairs?+
The IRC requires the landing depth to be at least equal to the stair width (typically 36 inches minimum) and the width to be at least as wide as the stairway it serves.
Can I use winder treads instead of a landing?+
Yes, you can replace the flat landing with three winder treads to save space. However, this changes the stair classification and the tread requirements differ - see our Winder Calculator for details.