Staircase / Ramp Angle Calculator
Calculate staircase dimensions and ramp slopes for building code compliance
Calculate Stairs or Ramp
How to Use the Staircase & Ramp Calculator
Getting Started
- Choose Type: Select staircase or ramp design
- Select Units: Choose metric (mm/m) or imperial (in/ft) measurements
- Enter Dimensions: Provide known measurements for calculations
- Check Compliance: Review building code compliance results
Staircase Design Guidelines
- Rise: Height of each step (100-200mm / 4-8 inches)
- Tread: Depth of each step (250-350mm / 10-14 inches)
- 2R + T Rule: Should equal 600-700mm (24-28 inches) for comfort
- Angle: Comfortable range 20-50 degrees, ideal 30-35 degrees
Ramp Accessibility Guidelines
- ADA Maximum: 8.33% slope (1:12 ratio) for accessibility
- Comfortable: 5% slope or less for general use
- Landings: Required every 9m/30ft for slopes over 5%
- Width: Minimum 900mm/36 inches for wheelchair access
Building Code Requirements
- Handrails: Required for stairs over 3 steps, both sides for width >44"
- Headroom: Minimum 2m/6'8" clearance throughout
- Landings: Required at top and bottom, minimum depth = stair width
- Nosing: Maximum 1.5" projection, rounded edges recommended
Frequently Asked Questions
What is the 2R + T rule for stairs?
The 2R + T rule states that twice the rise plus the tread should equal 600-700mm (24-28"). This ensures comfortable and safe stair dimensions.
What slope is best for a wheelchair ramp?
For accessibility, maximum 8.33% (1:12 ratio). For comfort, 5% or less is preferred. Steeper slopes require more frequent landings.
How do I calculate the number of steps needed?
Divide total rise by optimal step rise (175mm/7"). Round to nearest whole number, then recalculate actual step rise by dividing total rise by number of steps.
Why does my staircase show as non-compliant?
Common issues: rise too high/low, tread too shallow/deep, angle too steep/shallow, or 2R+T rule violation. Adjust dimensions to meet building codes.
Do I need landings for my ramp?
Yes, landings are required every 9m/30ft for slopes over 5%, at direction changes, and at doors. Minimum size is 1.5×1.5m (5×5ft).
Can I use this for spiral or curved stairs?
This calculator is for straight stairs only. Spiral and curved stairs have additional code requirements and need specialized design.
Related Construction Calculators
- Beam Load Calculator - Calculate stair stringer and support beam requirements
- Concrete Volume Calculator - Calculate concrete for ramp construction
- Steel Weight Calculator - Calculate handrail and railing weights
- Paint Coverage Calculator - Estimate paint for stair and ramp finishing