Stairs Calculator
Designing stairs the right way is critical for safety, comfort, and code compliance. Our free online Stair Calculator helps you calculate stair rise, run, stringer length, step height, tread depth, and stair angle in seconds. Whether you’re a seasoned contractor or a DIY enthusiast, this tool saves time and removes guesswork from stair construction.
This page includes both an Automatic Stair Calculator and a Manual Stair Calculator so you can choose the workflow that suits your project. Enter your dimensions, click calculate, and get instant, code-ready results.
Automatic Stair Calculator
Stair Results
| Number of Steps (Risers): | |
| Steps on Stringer [D]: | |
| Height of First Step [E] (in): | |
| Height of Typical Step [F] (in): | |
| Stringer Placement [H] (in): | |
| Total Run [G] (in): | |
| Stringer Length (in): | |
| Stair/Rail Angle (°): |
How to Use the Automatic Stair Calculator Properly
Manual Stair Calculator
Stair Results
| Step Height [F] (in): | |
| Tread Depth [B] (in): | |
| Steps on Stringer [D]: | |
| Height of First Step [E] (in): | |
| Stringer Placement [H] (in): | |
| Stringer Length (in): | |
| Stair/Rail Angle (°): |