Size your power station, battery and solar panels without guesswork

Whether you're preparing for outages, camping off-grid or setting up an RV, these free tools turn your device list into real numbers: watt-hours, inverter watts and solar panel size. Every formula is shown, so you can check the math yourself.

Calculators

Guides

How we approach this

Most sizing advice online is either a sales pitch for a specific product or a vague "it depends." We try to do better by showing the formulas, using conservative assumptions, and telling you which spec to check on your own equipment. Read our editorial policy to see how the tools and guides are made and checked.