How to Use This Calculator
Check the box next to anything you plan to run, then adjust the wattage and hours to match your actual gear — the defaults are typical averages, but the sticker on your device (or its manual) will give you an exact number. Multiply that out over a day and you get watt-hours (Wh), which is the same unit power stations and batteries are rated in.
A few things worth knowing as you plug in numbers:
- Compressor appliances like fridges don't run constantly — they cycle on and off, so the "hours/day" default is already an estimate of actual run time, not the full 24 hours.
- Surge vs. running watts — this tool calculates running (continuous) watts. Motors and compressors can briefly draw 2–3x more on startup, which matters for generator and inverter sizing but not for your daily Wh total.
- Round up, not down — batteries lose some capacity to inverter inefficiency and cold weather, so treat your total as a floor, not a ceiling.
Once you have your daily Wh number, head over to our Solar guides to figure out panel sizing, or check back soon for the dedicated Battery Runtime and Solar Panel Size calculators.