⚡ Free Interactive Tool
Off-Grid Power & Solar Runtime Calculator
Avoid buying an undersized battery that cuts out at 3 AM. Select your appliances below to estimate your exact daily Wh budget and recommended inverter output.
Off-Grid Appliance Runtime Sizing Calculator
Calculates real-world operating hours factoring in measured inverter conversion losses (85% usable efficiency).
EcoFlow DELTA Pro 3
Wh
Quick Presets:
Watts →
~23.2 Hrs
🫁
~87 Hrs
CPAP Machine
40W (DC Port)
🧊
~58 Hrs
12V Camping Fridge
60W (DC Port)
🛰️
~69.6 Hrs
Starlink Mini / Internet
50W (AC Inverter)
💻
~53.6 Hrs
MacBook / USB-C Laptop
65W (DC Port)
🍳
~2.3 Hrs
Portable Induction Cooker
1500W (AC Inverter)
♨️
~3.5 Hrs
Compact Microwave
1000W (AC Inverter)
🔥
~2.9 Hrs
Ceramic Space Heater
1200W (AC Inverter)
📱
~232.1 Hrs
Camp Lights & Smartphone
15W (DC Port)
How Our Calculation Algorithm Works
Nominal power station capacities are rarely 100% usable due to the DC-to-AC pure sine wave inverter conversion loss (typically 12% to 18%). Our calculator factors in real-world 85% discharge efficiency and 20% surge safety headroom so your power bank runs your gear without tripping over-current protection.