Portable power Wh calculator
Size a camping, van-life, or home-backup power station from device watts × hours (or Wh/day). Transparent losses for inverter efficiency, usable DoD, and planning buffer.
WattNeeds defaults: inverter efficiency η=0.90, DoD=0.90, buffer=0.15.
One-liner: nameplateWh = (whPerDay × days × 1.15) / (0.90 × 0.90).
Always re-check continuous watts and surge against the station inverter.
Disclaimer: Estimates only — not professional electrical advice and not medical advice (including CPAP). Verify continuous watts, surge, and usable Wh against manufacturer specs before you buy or rely on a station for critical loads.
Devices
Enter either Watts + hours/day or Wh/day (leave watts/hours blank if using Wh/day). Fridges: use average Wh/day, not compressor W × 24.
Autonomy & losses
Optional runtime check
Quick links
- Camping fridge Wh needs — average daily energy, not nameplate watts
- CPAP overnight sizing — estimates + safety notes
- Home outage essentials — router, lights, fridge, phones
- Van-life daily Wh budget — fridge + lights baseline
- EcoFlow vs Jackery vs Bluetti — how to compare (no fake rankings)
Where to check pricing
As an Amazon Associate, we earn from qualifying purchases at no extra cost to you. EcoFlow, Jackery, and Bluetti partner programs are not live yet.
See on Amazon EcoFlow — Coming soon Jackery — Coming soon Bluetti — Coming soon