J Ask Jack — Tool Finder ›
Full Calculators Directory Index ›
Concrete & Masonry
Roofing & Framing
Stairs & Railings
Metalwork & Fabrication
Woodworking & Design
Interior & Finishing
Electrical, HVAC & Solar
Structural & Safety
Landscape & Site
Planning & Contracts
Metric Units

Glossary: Slope Factor

Slope Factor is defined as: A ratio of inclined rafter length to horizontal run, calculated as: Multiplier = √(Rise² + Run²) ÷ Run. It is used by contractors and architects to scale flat blueprint footprint areas to true sloped roof surface areas.

Related Active Calculator:

📐 Roof Pitch Calculator