Ramp Calculator and 2012 IRC Building Codes

This ramp calculator is ideally suited for planning and building a wheelchair accessible handicap ramp. It includes 2012 IRC building code requirements.

2012 IRC for Ramps

These building codes are based on section R311.8.1 on page 61 of the 2012 International Residential Code.

  • Ramps must have a maximum slope of one inch per foot. There is an exception that allows an absolute maximum of one inch rise for every eight inches of run because of site constraints.
  • If the ramp exceeds a slope of one inch per foot then there must be a handrail. The handrail must remain continuous. It must be at a height between 34″ and 38″.
  • There must be a three foot by three foot landing at the top and bottom of every ramp. There must also be a landing where ramps change direction or a door swings out over the ramp.

Use a Framing Square

A framing square is invaluable for building a ramp. Simply place the tongue on the calculated rise and place the blade on the selected run and the angle of the cut is set. If you are using speed square then make the angles 4.76º, 5.71º, or 7.13º respectively.

Know that ramp surfaces can become very slick under certain circumstances (ice, snow, water). Do not lay out your ramp so that it could become a launching pad!

A wheelchair ramp can change directions as many times as necessasry.