Solar Roof Space & Weight Calculator
Roof area is panel count × width × height. Add walking gaps and setbacks yourself. Weight is nameplate module mass only — rails, ballast and snow are extra.
Inputs
Results
- Module area
- 11.88m²
- Module mass
- 126kg
Recommended gear
Engineering methodology
Module area = panel count × width × height (m²). Module mass = panel count × mass per panel (kg). Walking gaps, fire setbacks, rails, ballast and snow are not included. A typical 400 W module is on the order of 1.1 × 1.8 m and about 18–22 kg.
Frequently asked questions
Does this roof-space number include walkways between panels?
No. It is N × width × height of the glass. Add manufacturer spacing, ridge/eave setbacks and any local fire-access pathways on top.
Is panel weight enough for a structural roof check?
No. Rails, clamps, ballast, snow and wind uplift are extra dead and live loads. Confirm ratings with a qualified person. This is geometry and nameplate mass only.
How much area does a 6-panel 400 W array need?
At 1.1 m × 1.8 m, six modules are 11.88 m² of glass and about 126 kg if each panel is 21 kg—before racking.
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