General Pitch Calculator
Calculate slope, angle, and grade percentage for ramps, stairs, grading, and pipes with ease.
| Application | Ratio | Pitch (X:12) | Angle (°) | Grade (%) | Code / Authority |
|---|---|---|---|---|---|
| ADA Accessible Ramp | 1:12 | 1:12 | 4.8° | 8.33% | US Title III ADA Mandate |
| Plumbing Gravity Drain | 1:48 | 0.25:12 | 1.2° | 2.08% | Uniform Plumbing Code |
| Standard Interior Stairs | 7:11 | 7.64:12 | 32.5° | 63.6% | IBC Stair Code Section 1011 |
| Concrete Driveway Limit | 1:10 | 1.2:12 | 5.7° | 10.0% | Civil Vehicle Clearance |
| Concrete Sidewalk Cross-Slope | 1:50 | 0.24:12 | 1.15° | 2.00% | PROWAG Drainage Limit |
How the Slope, Angle, and Grade Calculations Work
How to use this calculator: enter any rise and run in the units you have — fractional inches like 6 1/2 are supported — and the pitch ratio, angle, grade percentage, and 1:N ratio update in real time, with the schematic redrawing to scale. The code presets (ADA ramp, IBC stairs, drainage, driveway) load standard ratios so you can check an existing slope against the applicable requirement.
Grade percent and ratio are the two formats builders use interchangeably: drainage and ADA work is specified in ratios (1:12, 1/4 per foot), while civil and roadway work is usually specified in percent. Both describe the same geometry — use whichever your plan set or local code cites, and always verify against the governing standard for your project.