Roof Pitch & Angle Converter
Instant conversion between degrees, ratios, and percentages
Degrees30.00°
X-in-126.93 : 12
Slope %57.74%
Conversion Formula: To convert a known rise and run into degrees: Degrees = arctan(Rise ÷ Run) × (180 ÷ π). To convert an American X-in-12 pitch into degrees: Degrees = arctan(X ÷ 12) × (180 ÷ π). For example, a 6:12 pitch equals arctan(6 ÷ 12) = arctan(0.50) = 26.57°.
Conversion Quick Reference Matrix
| X-in-12 Pitch | Slope Ratio (1 in X) | Slope Gradient (%) | Degrees of Angle (°) | Pitch Multiplier Factor |
|---|---|---|---|---|
| 2 : 12 | 1 in 6.00 | 16.67% | 9.46° | 1.0138 |
| 4 : 12 | 1 in 3.00 | 33.33% | 18.43° | 1.0541 |
| 6 : 12 | 1 in 2.00 | 50.00% | 26.57° | 1.1180 |
| 7 : 12 | 1 in 1.71 | 58.33% | 30.26° | 1.1577 |
| 8 : 12 | 1 in 1.50 | 66.67% | 33.69° | 1.2019 |
| 9 : 12 | 1 in 1.33 | 75.00% | 36.87° | 1.2500 |
| 12 : 12 | 1 in 1.00 | 100.00% | 45.00° | 1.4142 |
📚 Primary Technical Sources & British Standards
- BS 5534:2014+A2:2018: Code of practice for slating and tiling for pitched roofs and vertical cladding. British Standards Institution.
- BS 5250:2021: Management of moisture in buildings — Code of practice. British Standards Institution.
- BS 6229:2018: Flat roofs with continuously supported flexible waterproof coverings — Code of practice.
- NHBC Standards Chapter 7.2: Pitched Roofs — Minimum pitches, rafter timber sizing, batten gauges and fixing specifications.
- UK Manufacturer Technical Literature: Marley Technical Handbooks, BMI Redland Fixing Guides, CUPA Pizarras Slate Technical Manuals.
Last technical audit date: 17 August 2026.