Solar Calculators by Van Type
Roof space is the hard limit on how much solar a van can carry, and it varies a lot between models. Each page below loads a representative build for that van so you can adjust from a sensible starting point rather than a blank form.
Mercedes Sprinter 144
Roughly 55–70 sq ft of usable roof — room for 400–600 W of rigid panels once a fan and vents are placed.
Mercedes Sprinter 170
About 75–95 sq ft of roof — enough for 600–800 W without crowding vents.
Ford Transit
Around 60–90 sq ft depending on wheelbase and roof height — typically 400–700 W.
RAM ProMaster
The widest roof of the class — 65–95 sq ft, friendly to 500–800 W.
Skoolie (bus conversion)
A school bus roof is huge — 120–250 sq ft — so panels rarely limit you; battery and budget do.
Truck camper
Compact — 20–40 sq ft — so 200–400 W is typical, often supplemented by DC-DC charging.
Not sure which applies?
The van you drive changes the roof area and the weight you can carry, but not the arithmetic. If your model is not listed, start from the calculator and enter your own appliances — the sizing method is identical. Where you park matters too: see solar by location for how peak sun hours change the array, and battery sizing for the bank behind it.