Size your energy needs before comparing equipment.
Understand the limits
Required nominal watt-hours = Σ(device watts × hours) ÷ efficiency. The default 85% is an illustrative allowance for conversion and other losses. Actual runtime depends on temperature, battery condition, inverter idle use, and device behavior. Measure real loads when possible.
Capacity (Wh) is energy. Continuous output (W) is how much a source can deliver at once. Surge output must cover startup demands, which this tool does not predict. If all listed loads run together, add their watts and compare to continuous output separately. Verify medical-device requirements with the manufacturer and provider; this estimate is not a medical backup guarantee.
Sources & reading
Source check: November 1, 2026. Educational synthesis; no government affiliation. During an emergency, follow current local instructions.