Enter your daily energy usage and available roof space to get a recommended panel wattage and battery capacity for your rig.
Assumes flat, unshaded roof-mount panels; flexible or portable panels on partly shaded roofs will need more rated wattage to compensate.
RV and van solar has tighter constraints than a house — limited roof area, weight limits, and the need to fully recharge in a single day of driving or parking in the sun. This scales your daily watt-hour usage by sun hours to size the array, then applies your chosen autonomy days to size the battery bank, the same way our off-grid calculator handles stationary systems.
RV solar sizing is a genuinely different problem from home solar — roof space and weight are hard constraints, not just cost trade-offs, and daily usage patterns (a weekend trip versus full-time living) change the right battery-to-panel ratio significantly. This tool reflects that mobile-specific math rather than treating your rig like a small house.
A 400-600W array — enough for moderate daily use with a fridge, lights, and device charging — usually needs 20-30 square feet, which fits most van and small RV roofs.
The 'days of autonomy' setting handles that — 2 days is a common buffer for occasional overcast weather without needing to run a generator.
Size for boondocking (no shore power) if that's how you'll primarily use the rig — a system sized for occasional off-grid stretches with hookups as the norm can use a smaller, cheaper setup than one meant for extended full-time boondocking.