Know what goes into each estimate

Use numbers you can check

Enter values from your device label, manual, energy label, or your own measurements. The Daily Power Consumption Calculator accepts running watts, DC volts and amps, AC volts and amps with power factor, and kWh per day or year. Identify how each device is powered to see separate DC, inverter AC, other, and unassigned energy totals in Wh/day. Use your own device’s numbers; we don’t provide wattages for specific models.

Different numbers mean different things

Battery capacity, usable energy, AC and DC loads, inverter losses, continuous watts, and startup surge are distinct. Each calculator explains the differences that matter for its calculation and the assumptions it makes.

Results are estimates

Actual battery runtime and solar production can vary with equipment condition, temperature, weather, shade, and how appliances are used. A result that falls within a selected power limit is not a certification that an electrical installation is safe.

Formulas and sources

Each calculator includes its own method, assumptions, defaults where used, and sources.

Battery and solar tools explain the energy balance. RV Power System Checker compares daily energy drawn from the battery with estimated solar production and available battery capacity. Battery Runtime explains its usable-energy and inverter assumptions. Battery Size estimates the capacity needed for daily DC and AC use. Solar Size estimates rated panel wattage from sun hours and system losses, while Solar Charging Time estimates the sun needed to restore battery energy.

Load calculators focus on equipment limits. Inverter Size and Generator Size separate continuous loads from startup surge. Can I Run This on My Inverter? and Can I Run This on My Generator? compare your loads with the ratings you enter. 30 Amp RV Shore Power compares running AC current with the 30A service limit. 50 Amp RV Shore Power checks running AC current on each leg, L1 and L2, against its own 50A limit.

Energy-use and conversion tools show how the numbers are calculated. Daily Power Consumption explains how each input becomes Wh/day. Ah to Wh and Wh to Ah convert nominal battery capacity. Watts to Amps and Amps to Watts explain their AC and DC formulas.