This off-grid load calculator lets you build a device-by-device energy budget organized by room. It accounts for ghost loads (standby power draw), inverter overhead losses, and gives you totals in Wh/day, Wh/week, and kWh/month — the numbers you need for accurate. This calculator is designed to help you estimate your daily energy usage while living off-grid in a motorhome, campervan, caravan, or boat. By entering your appliance usage, it provides tailored recommendations for the ideal inverter size, battery capacity, and solar panel array needed to keep you. Add devices by room, set usage hours, and determine your daily, weekly, and monthly power consumption including ghost loads and inverter overhead. For example, a single 50 Watt fan operating for 3 hours per day will result in 150 Wh per day (50W x 3 hours = 150Wh). Below is a combination of multiple calculators that consider these variables and allow you to. A load table lists all the common appliances, the power ratings (wattage) and the average runtime per day.