Stair Calculator
Calculate the number of steps, exact riser height, total run length, and stair angle from your floor-to-floor height. Designed for typical Nepali residential staircases following Nepal National Building Code guidelines.
How to use this calculator
- Measure your floor-to-floor height — slab top to slab top, not floor finish to floor finish.
- Pick a target riser. 150–180 mm is the comfortable range for residential stairs in Nepal; 165 mm is a common default.
- Set tread width. Anything under 250 mm becomes uncomfortable; 280–300 mm is typical.
- Read off the actual riser the calculator settles on, since the floor height rarely divides cleanly into your target.
FAQ
What is a comfortable stair riser height in Nepal?
For residential staircases in Nepal, riser heights between 150 mm and 180 mm are comfortable. A riser of 165 mm with a tread of 280 mm is a common default that satisfies the Nepal National Building Code recommendation for daily use.
What does the Blondel rule mean?
The Blondel rule is a comfort check: 2 × riser + tread should fall between 600 mm and 640 mm. If the result is in that range, the stair feels natural to walk on. Values outside the range usually mean the stair is either too steep or has an awkwardly long stride.
How many steps for a 9-foot floor height?
A 9-foot floor height equals about 2,743 mm. With a 165 mm target riser, you get 17 steps with an actual riser of about 161 mm and a total run of 4,480 mm if the tread is 280 mm.
How do I plan a stair with a landing?
If your available run length is less than the calculated total run, split the staircase with a landing. The landing should be at least as wide as the stair and is typically placed roughly halfway up. After splitting, design each flight independently using this calculator with the partial floor height.