Stair Calculator

Stair Calculation Options

Mount (i)

Standard Flush

Tread Thickness (i)

Display headroom calculation details

Your Stairs

Total Rise (i)

Number of Steps (i)

Rise (per step)

Run (per step)

Results

Total Run

Bottom Step Rise

Stringer Length

Angle

deg

Key Features

✔ Auto-calculates steps, rise, run, and angle—just enter your total rise and tread run.
✔ Supports Standard and Flush Mount to adjust bottom riser and stringer length accordingly.
✔ Dynamic headroom checker to help you meet safety codes and avoid low-clearance issues.
✔ IRC-compliant safety warnings for riser height, tread depth, and overall stair comfort.
✔ Unit flexibility with support for inches, feet, meters, and centimeters across all inputs and outputs.
✔ One-click result sharing for quick communication with your team or builder.

How to Use It

Enter Your Total Rise:
Input the full vertical height from the lower floor to the upper level. The calculator will estimate the ideal number of steps if you leave that field blank.
Adjust Stair Settings:
Choose the mount type (Standard or Flush) and enter your desired tread run. You can also set tread thickness for more accurate bottom step height.
View Results Instantly:
Get real-time values for total run, rise per step, stringer length, angle, and bottom riser height—all dynamically calculated.
Enable Headroom Check (Optional):
Toggle the headroom feature to ensure your stair design meets code clearance requirements based on floor thickness and stairwell opening.
Review Code Warnings:
If any part of your stair layout violates building codes (e.g. riser too high or tread too shallow), you’ll be alerted with clear warnings so you can fix it before building.
Copy and Share Results:
Click “Share Result” to copy all the calculated values and alerts to your clipboard. Ideal for planning, quoting, or sending specs to contractors.

Build with Precision

The Stair Calculator is designed for precision, safety, and simplicity. Whether you're building indoor stairs, exterior steps, or a deck staircase, this tool ensures your design is safe, comfortable, and code-compliant.

Start planning smarter with the LS Stair Calculator today.

Stair Calculator