Canopy Clearance Calculator
Calculate the vertical clearance beneath a canopy, awning, or overhead structure based on its mounting height, slope, and horizontal projection.
Vertical height from ground to the highest point where the canopy is attached.
How far the canopy extends outward from the wall.
Downward angle of the canopy from horizontal (0° = flat).
Thickness of the canopy frame/structure at its lowest edge.
Formula
Step 1 — Vertical drop at outer edge:
vertical_drop = projection × tan(slope°)
Step 2 — Soffit height at outer edge (before thickness):
soffit_height = mount_height − vertical_drop
Step 3 — Net clear height (clearance):
clearance = soffit_height − (thickness_in ÷ 12)
All distances in feet; slope converted to radians for trigonometry.
Assumptions & References
- The canopy is a planar, uniformly sloped surface attached at the wall.
- Clearance is measured at the lowest point — the outer (free) edge of the canopy.
- Slope is measured as a downward angle from horizontal (positive = sloping away from wall downward).
- IBC 2021 §1003.3 requires a minimum 80 in (6.67 ft) headroom in walking surfaces; many jurisdictions enforce 84 in (7 ft) for exterior canopies and awnings.
- ADA Standards §307.4 requires protruding objects to provide at least 80 in (6.67 ft) of vertical clearance.
- Structural thickness is subtracted from the soffit height to give the true clear dimension beneath the canopy frame.
- This calculator does not account for drainage gutters, lighting fixtures, or signage hung below the canopy.