Staircase Calculator Riser Tread India
Staircase Calculator
Calculate stair steps from floor height, riser and tread — NBC India comfort check with Blondel formula (2R + T).
Your data never leaves your browser — all processing happens locally on your device.
NBC India: riser max 190 mm, tread min 250 mm for residential. Verify local building bylaws and fire exit requirements for commercial projects.
Typical: 150–175 mm residential
Typical: 250–300 mm
About this tool
Calculate the number of stair steps from floor-to-floor height, riser and tread dimensions. Adjusts riser height to equal steps, checks NBC India comfort range using the Blondel formula (2R + T = 550–700 mm), and shows total run length and stair angle. For architects designing residential and commercial staircases in India. Free browser calculator — verify against local building bylaws.
How to use the Staircase Calculator
- 1
Enter floor height
Add floor-to-floor height in metres or feet.
- 2
Set riser and tread
Typical residential: 150 mm riser, 250 mm tread.
- 3
Review steps and comfort
See step count, Blondel check and total run length.
Frequently Asked Questions
What is the Blondel formula?
2R + T (twice riser plus tread) should be 550–700 mm for comfortable stairs. NBC India recommends riser max 190 mm and tread min 250 mm.
Why is actual riser different from input?
Steps must be equal — we divide floor height by the nearest whole number of steps and recalculate riser.
Does this include landing?
No — enter clear floor-to-floor height. Mid-flight landings add to total run separately.
Commercial vs residential?
Commercial buildings may have different NBC requirements for fire exits — verify with your fire consultant.