Stair Calculator

Stair Calculator is a clean, fast tool for planning a staircase — completely offline. Enter the total rise between floors, choose how you want to set the steps, and the app instantly works out every dimension you need to lay out a comfortable flight.

WHAT YOU CAN DO
• Enter the total rise (floor to floor) in centimetres
• Set the number of steps, or aim for a target riser height
• Set a target tread depth, or work back from a total run
• See riser height, tread depth, number of steps and treads
• Get total run, stringer (diagonal) length and the stair angle
• View a to-scale side-profile diagram of the whole flight

COMFORT CHECKS BUILT IN
The app flags whether your riser and tread land in comfortable ranges (riser about 15–20 cm, tread about 25–30 cm) and checks the classic rule that 2 × riser + tread should sit between 60 and 64 cm — the proportion that matches a natural stride as you climb.

LEARN AS YOU GO
A built-in Learn tab explains rise versus run, comfortable stair ratios, the geometry behind the stringer and angle, and the general code ranges to keep in mind while you plan.

CLEAR AND METRIC
Everything uses consistent metric units (centimetres), clearly labelled. Invalid input is guarded so you always get a sensible answer.

GENERAL GUIDANCE — VERIFY YOUR CODES
The results are general guidance for planning and learning, not a substitute for professional advice. Building requirements for risers, treads, headroom and handrails vary by country and jurisdiction. Always verify your dimensions against your local building codes before construction.

PRIVACY
The app collects no personal data and works fully offline — your measurements never leave your device. Ads are served by Google AdMob, which may use an advertising identifier as described in Google's policies.

Light and dark themes, a tiny download, and no clutter. Download Stair Calculator and lay out your stairs with confidence.