Calculate the number of risers and treads, the actual riser height, and the total horizontal run needed for a staircase between two floors.
How to Use the Staircase Calculator
Enter the "Total Rise" - the vertical floor-to-floor height in millimeters.
Enter your "Desired Riser Height" - typically 150-190mm.
Enter your "Desired Tread Width" - typically 250-300mm.
Click "Calculate Staircase" to see the number of risers/treads, the actual riser height, and whether the design is comfortable to walk on.
Frequently Asked Questions
The number of risers must be a whole number, so the calculator rounds your desired riser height to the nearest riser count that evenly divides the total rise, then recalculates the exact riser height needed - this ensures every step in the staircase is the same height.
The top riser is typically "absorbed" into the upper floor level, so a staircase with N risers only has N-1 treads, since the top floor itself acts as the final step.
It's a widely used rule of thumb for comfortable stair proportions: twice the riser height plus the tread width should fall between roughly 550mm and 700mm, matching a natural walking stride.
Yes, it's completely free and requires no sign-up.