Sizing calculator

How much backup power do you need?

Choose your devices, a backup window, and what you are planning for. Advanced electrical controls are optional.

POWER NEEDS

Example planning values — edit them to match your actual devices.

DEVICE 1
Source: U.S. Department of Energy appliance tableUses a 50% cycling duty-cycle planning assumption. The 1,500 W startup value is a conservative 3× allowance, not a universal appliance specification. Verify the nameplate or manufacturer documentation.
DEVICE 3
Source: ENERGY STAR certified light-fixture listingExample certified LED fixture value; edit this to match the wattage printed on each lamp.
DEVICE 4
Source: U.S. Department of Energy appliance tableActual draw varies widely with screen size, brightness, and display technology.
DEVICE 5
Source: U.S. Department of Energy-hosted plug-load studyRounded planning value based on a measured 57.5 W laptop example; use the charger label or a watt meter for your device.
LOAD SUMMARY
Devices selected
6
Estimated energy
2,155 Wh
After conversion losses
2,536 Wh
Recommended rated capacity
~2,984 Wh+
Maximum simultaneous load
714 W
Startup / surge requirement
1,714 W

Energy uses each row’s runtime, quantity, and duty cycle. Output sums checked devices; unchecked devices are treated as one-at-a-time loads. Startup replaces that device’s running draw during its start event.

YOUR ESTIMATED NEED
Battery size
~3.0 kWh+
Power output
~714 W+
Startup capability
~1,714 W
See calculation details
Device energy
2,155 Wh
After 85% conversion efficiency
2,536 Wh
After separate 15% reserve
2,984 Wh
RECOMMENDED MATCHES
How scoring works
1
Anker SOLIX F3000
3,072 Wh · 3,600 W · 91.5 lb
Match Score 82 / 100
Why this matches
  • Meets your 714 W continuous running requirement.
  • Battery capacity is closely sized to your requested runtime.
  • Its surge rating covers your estimated 1,714 W startup requirement.
  • Includes UPS support for backup-power use.

Trade-off: At 91.5 lb, it is difficult to carry frequently.

Score breakdown
Capacity Fit 100Output Fit 60Use-case Fit 100Portability 5Feature Fit 81
View product details
Check price at manufacturer · Anker SOLIX USExact product listing at Anker SOLIX US — availability may change
Check Price on Amazon.comExact product listing at Amazon US — availability may change
2
BLUETTI Elite 300
3,014.4 Wh · 2,400 W · 57.98 lb
Match Score 80 / 100
Why this matches
  • Meets your 714 W continuous running requirement.
  • Battery capacity is closely sized to your requested runtime.
  • Its surge rating covers your estimated 1,714 W startup requirement.
  • Includes UPS support for backup-power use.

Trade-off: At 57.98 lb, it is difficult to carry frequently.

Score breakdown
Capacity Fit 100Output Fit 76Use-case Fit 71Portability 18Feature Fit 78
View product details
Check Price on Amazon.comExact product listing at Amazon US — availability may change
Check price at manufacturer · BLUETTI USExact product listing at BLUETTI US — availability may change
3
EcoFlow DELTA Pro 3
4,096 Wh · 4,000 W · 113.5 lb
Match Score 78 / 100
Why this matches
  • Meets your 714 W continuous running requirement.
  • Battery capacity is closely sized to your requested runtime.
  • Its surge rating covers your estimated 1,714 W startup requirement.
  • Includes UPS support for backup-power use.

Trade-off: At 113.5 lb, it is difficult to carry frequently.

Score breakdown
Capacity Fit 96Output Fit 60Use-case Fit 100Portability 5Feature Fit 62
View product details
Check price at manufacturer · EcoFlow USExact product listing at EcoFlow US — availability may change
Check Price on Amazon.comExact product listing at Amazon US — availability may change
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