Shape
Pitch
Overhangs
Roof Area ??? (Pitch-aware)
Calculate sloped area from plan dimensions and pitch. Split complex roofs into sections and sum them.
??s are horizontal (plan) lengths, not rafter length.
Assumptions
- Dimensions are plan (horizontal) lengths, not rafter lengths.
- Overhangs are treated as horizontal projections.
- Hip, gable/hip mixes, valleys, dormers, etc. should be handled by sectioning.
Unit
Unit is fixed on the right of each input.
Roof section
Drag to reorder
??s
- r = Rise/Run
- θ = atan(r)
- k = 1 / cos(θ) = sqrt(1 + r^2)
- Shed: Ap = (L + 2g) × (D + e + e2)
- Gable: Ap = (L + 2g) × (S + 2e)
- Sloped area: As = Ap × k
????
- This tool is a calculation aid and not a substitute for design, regulations, contracts, or safety requirements.
- Preset values are examples and will vary by conditions.
?? ?? ??
What if the gable left/right spans differ?
Use the advanced option to enter left and right half spans.
How do I enter sun pitch?
You can enter 3.5 or 3 sun 5 bu.
Are inputs rafter lengths?
???. ??s are plan (horizontal) lengths.