How this calculator works
Usable energy (Wh) = rated capacity × usable capacity %
Delivered energy (Wh) = usable energy × conversion efficiency %
Runtime (hours) = delivered energy ÷ total load (W)The defaults (95% usable × 90% efficiency ≈ 85.5%) are close to the 0.85 factor that EcoFlow and other makers use for AC devices. Choosing a model fills in its rated capacity and continuous AC output from EcoFlow’s published specifications — check them on the EcoFlow buyer’s guide.
Example (estimate). The EcoFlow DELTA 3 Classic is rated 1,024 Wh. Running a 60 W fan, a 10 W router and two 9 W LED bulbs (88 W in total): 1,024 × 0.855 ÷ 88 ≈ 9 h 57 min.
Not sure which model you need?
Take the Which EcoFlow should I buy? quiz — tick your appliances and it matches models by output, surge rating and capacity.
Where to buy each EcoFlow model
Links go to each model’s Shopee or Lazada listing. Prices and stock change — check the listing before you buy.
| Model | Capacity | AC output | Solar input | Buy |
|---|---|---|---|---|
| RIVER 3 (UPS) | 245 Wh | 300 W | 110 W | |
| RIVER 3 | 245 Wh | 300 W | 110 W | |
| RIVER 2 | 256 Wh | 300 W | 110 W | |
| RIVER 3 Plus | 286 Wh | 600 W | 220 W | |
| RIVER 2 Max | 512 Wh | 500 W | 220 W | |
| RIVER 3 Max | 572 Wh | 600 W | 220 W | |
| RIVER 2 Pro | 768 Wh | 800 W | 220 W | |
| RIVER 3 Max Plus | 858 Wh | 600 W | 220 W | |
| DELTA 3 1000 Air | 960 Wh | 500 W | 500 W | |
| DELTA 3 1000 Air (UPS) | 960 Wh | 500 W | 500 W | |
| DELTA 3 Classic | 1,024 Wh | 1,800 W | 500 W | |
| DELTA 3 | 1,024 Wh | 1,800 W | 500 W | |
| DELTA 3 Plus | 1,024 Wh | 1,800 W | 1,000 W | |
| DELTA 3 (1500) | 1,536 Wh | 1,800 W | 500 W | |
| DELTA 3 2000 Air | 1,920 Wh | 1,000 W | 1,000 W | |
| DELTA 3 Max | 2,048 Wh | 2,400 W | 500 W | |
| DELTA 3 Max Plus | 2,048 Wh | 3,000 W | 1,000 W | |
| DELTA 3 Ultra Plus | 3,072 Wh | 3,600 W | 1,600 W | |
| DELTA Pro | 3,600 Wh | 3,600 W | 1,600 W | |
| DELTA Pro 3 | 4,096 Wh | 4,000 W | 2,600 W | |
| DELTA Pro Ultra (Inverter + 1 Battery) | 6,144 Wh | 6,900 W | — |
Limitations
- Assumes all devices run continuously at the watts you enter.
- Doesn’t model start-up surges, idle inverter draw, temperature or battery ageing.
- Specs are from EcoFlow’s official pages on the date shown in our buyer’s guide; models and specs can change.