CalcVind

Staircase Calculator

Number of steps, riser height and tread for a staircase

Your Staircase

India's National Building Code: residential risers up to 19 cm, treads at least 25 cm.

Staircase Plan

18Steps (risers)
16.7 cm (6.56 in)Riser height
17Treads
4.59 m (15.06 ft)
Total run (horizontal)
5.48 m (17.99 ft)
Stringer length
33.2°
Angle
60.3 cm
2 × riser + tread
Comfortable
Comfort

Working

  1. Risers = ⌈300 ÷ 17⌉ = 18
  2. Riser height = 300 ÷ 18 = 16.67 cm
  3. Run = 17 treads × 27 cm = 459 cm
  4. Stringer = √(300² + 459²) = 548.3 cm
  1. 1
    Measure the total rise
    Finished floor to finished floor
  2. 2
    Set riser and tread
    Or keep the comfortable defaults
  3. 3
    Get the plan
    Steps, run, stringer and angle

How are stairs calculated?

Divide the total rise into equal risers no taller than your target, then add up the treads for the run. One fewer tread than risers, because the top floor is the last step:

Risers = total rise ÷ target riser (rounded up)

Riser = total rise ÷ risers

Run = (risers − 1) × tread

Comfort: 2 × riser + tread ≈ 60–65 cm

The comfort rule

Blondel's formula says twice the riser plus the tread should equal a normal stride, about 60–65 cm. A 17 cm riser with a 27 cm tread gives 61 cm, which feels natural to climb.

Headroom and landings

Allow at least 2.1 m of headroom above every step. A long flight of more than about 12–15 steps should have a landing in between.

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Frequently asked questions

How many steps for a 10 ft floor height?

A 10 ft (305 cm) rise needs 18 risers of about 16.9 cm, with 17 treads.

What is a standard riser height in India?

About 15–19 cm for homes. The National Building Code sets a maximum of 19 cm for residential stairs and a minimum tread of 25 cm.

What angle should stairs be?

Between about 30° and 37° is comfortable for most homes. Steeper stairs save space but are harder and less safe to use.

Sources

Last reviewed: October 2026