🏠 Roof Pitch Calculator
Instantly convert between rise/run, angle (°), percent (%), ratio (x:12), and rafter length — with unit selectors, tooltips, derivation, and PDF export.
Tip: You’ll need at least two independent values to compute everything.
Auto-calculated from any valid pair (or enter it as one of your knowns).
🧮 Step-by-step derivation
Enter at least two independent values (e.g., Rise & Run, or Angle & Run, or Rafter & Percent).
Formulas:
- rafter² = rise² + run²
- pitch = rise / run = tan(angle) = percent/100 = (x / 12)
📚 Reference & quick ranges
| Roof type | Typical x:12 | Angle (≈°) | Percent (≈%) |
|---|---|---|---|
| Flat (not perfectly flat) | 0.5–2 : 12 | ~2.4°–9.5° | ~4.2–16.7% |
| Low pitched | < 4 : 12 | < ~18.4° | < ~33.3% |
| Conventional | 4–9 : 12 | ~18.4°–36.9° | ~33.3–75% |
| High pitched | up to 21 : 12 | up to ~60° | up to ~175% |