About RVWatt

RVWatt is a free, independent calculator for sizing solar, batteries and inverters for RVs, camper vans and overland rigs. It is built in Hailey, Idaho, where winter sun is short and summer sun is long, which is exactly why it sizes systems month by month instead of from a yearly average.

How we keep it accurate

• Sun data comes from NASA POWER monthly climatology (2001–2025).
• Every formula is shown under "Show the math" in the calculator.
• The sizing engine is covered by automated tests that check each calculation against hand-worked answers.
• We don't sell equipment, and recommendations don't depend on any brand.

Who runs RVWatt

RVWatt is operated by RVWatt LLC, an Idaho limited liability company.

Contact

Email: [email protected]