Work out the number of risers, exact riser height and tread depth for a comfortable, code-compliant staircase — from the total floor-to-floor height.
Uses Blondel's Rule (2×riser + tread = 630mm), the standard architectural formula for a comfortable stride. Most Pakistani building byelaws require riser height between 150–200mm and tread depth between 250–300mm for residential stairs — check your local code.
A stair that's comfortable to climb keeps 2 × (riser height) + (tread depth) between roughly 600–650mm — too steep (tall risers, shallow treads) feels cramped and unsafe; too shallow (short risers, deep treads) needs an awkward extra half-step. This calculator targets 630mm, the commonly used midpoint.
You can't have a fractional number of risers, so the calculator rounds to the nearest whole number of risers first, then recalculates the exact riser height needed to reach your total floor-to-floor height precisely — every riser in a real staircase must be identical height, or it becomes a trip hazard.
Most residential codes cap riser height around 190–200mm maximum and require a minimum tread depth around 250mm. If this calculator's tread-depth result comes out below that, your riser height target is too tall for the available run — consider a longer staircase or a winder/landing.