Menu
Portable Power Station Size Calculator
Start from the devices you need to run, then size the station by watt-hours, output rating, surge, reserve, and charging plan.
Calculator
Start with a quick estimate, then switch to Advanced if you need multiple devices, startup surge, battery health, or cold-weather loss.
Loading calculatorPreparing calculator
This tool didn't load
Something blocked the calculator from starting. Check your connection or reload the page to try again.
Power station model
Battery capacity (Wh): 1024 WhContinuous output rating (W): 1800 WSurge output rating (W): 2700 W
Estimated runtime13h 3m8h 10m – 16h 13mEstimated runtime: 13h 3m, 8h 10m – 16h 13m
Output path
Estimated runtime
13h 3mEstimated runtime: 13h 3mThis setup has comfortable headroom for overnight use, assuming the wattage estimate is realistic.
Conservative8h 10m
Estimated13h 3m
Optimistic16h 13m
Conservative assumes harder conditions; optimistic assumes favorable conditions.
- This is an estimate. Real runtime changes with load, temperature, battery age, AC/DC output, and device behavior.
- Usable energy
- 783 Wh
- Average load
- 60 W
- Fixed station overhead
- Unknown (not included)
- Running watts
- 60 W
- Max surge
- n/a
Show your work
Rated Wh is reduced by efficiency, reserve, battery health, and temperature before it is divided by average load.
- Rated battery
- 1024 Wh
- Battery capacity (Wh): 1024 Wh
- Usable energy
- 783 Wh
- 1024 Wh x 85% x 90% x 100% x 100%
- Average load
- 60 W
- 60 W running, 60 W average after duty cycle and quantity
- Fixed station overhead
- Unknown (not included)
- 60 W / 85% = 70.6 W battery draw; fixed overhead is unknown and excluded
- Estimated runtime
- 13h 3m
- 783 Wh / 60 W = 13h 3m
- 1024 Wh nominal battery capacity
- AC inverter output path
- 85% conversion efficiency
- 10% reserve kept unused
- 60 W average load from 1 load
- 100% battery health
- 0% temperature loss
- Fixed station overhead unknown; not included
This link contains the numeric values you entered, but not custom load names.
Source-Backed Next Steps
Smallest matching record (8h)Jackery Explorer 600 v2
WattRunTime.com
WattRunTime estimate
Estimated runtime
13h 3mThis setup has comfortable headroom for overnight use, assuming the wattage estimate is realistic.Usable energy783 Wh
Average load60 W
Fixed station overheadUnknown (not included)
Running watts60 W
Max surgen/a
Runtime range
Conservative8h 10m
Estimated13h 3m
Optimistic16h 13m
Show your work
Rated Wh is reduced by efficiency, reserve, battery health, and temperature before it is divided by average load.
Rated battery1024 WhBattery capacity (Wh): 1024 Wh
Usable energy783 Wh1024 Wh x 85% x 90% x 100% x 100%
Average load60 W60 W running, 60 W average after duty cycle and quantity
Fixed station overheadUnknown (not included)60 W / 85% = 70.6 W battery draw; fixed overhead is unknown and excluded
Estimated runtime13h 3m783 Wh / 60 W = 13h 3m
Assumptions
- 1024 Wh nominal battery capacity
- AC inverter output path
- 85% conversion efficiency
- 10% reserve kept unused
- 60 W average load from 1 load
- 100% battery health
- 0% temperature loss
- Fixed station overhead unknown; not included
Warnings
- This is an estimate. Real runtime changes with load, temperature, battery age, AC/DC output, and device behavior.
Share URL
Best for
Choose a capacity class before buying.
Runtime worked example
A 1,024 Wh station at 85% AC efficiency with a 10% reserve leaves about 783 Wh usable. At a steady 60 W load, that works out to 13h 3m.
Change first
- Change watts first when you have a watt-meter reading; change efficiency when switching between AC and DC output paths.
- Check startup surge for motors, compressors, and pumps.
- Use measured watts for outage or medical-adjacent planning.
This calculator gives a planning estimate. Treat the result as a starting point, then refine it with measured watts, the device manual, and the station's current output limits.
Verify your watts
- Check the device label for running watts or input amps and volts.
- Use a plug-in watt meter for AC loads when the result matters.
- For cycling loads, measure long enough to capture on/off behavior.
Check output path
- AC inverter loads usually lose more energy than direct DC loads.
- Keep reserve for cold weather, battery age, and load changes.
- Do not treat label capacity as fully usable watt-hours.
Related Guides
Use these explainers when an assumption changes the runtime result.
Capacity guide
Usable Capacity vs Rated Capacity
Turn the required runtime into a capacity target with margin.
Margin guide
Reserve and Battery Health
Turn the required runtime into a capacity target with margin.
Electrical units
Watt-Hours, Amp-Hours, and Voltage Explained
Turn the required runtime into a capacity target with margin.
Related Calculators
Use the related tools when charging, sizing, surge, or power path changes the answer.
FAQ
These answers keep the estimate grounded in assumptions instead of pretending runtime is exact.
Is a 1000Wh station really one kilowatt-hour usable?
Not for AC loads. A 1000Wh station at 85% efficiency with a 10% reserve gives about 765Wh usable for the load.
Why is real runtime lower than the label capacity?
Battery label capacity is nominal. Inverter losses, DC conversion losses, reserve settings, cold weather, battery age, and changing device loads all reduce real runtime.
How do you calculate portable power station runtime?
Use usable watt-hours divided by average load watts. For AC loads, a practical first-pass formula is battery Wh x efficiency x reserve factor divided by device watts.
Should I reserve 20% battery?
A 10% to 20% reserve is a practical buffer for uncertainty, startup spikes, and avoiding a completely empty station during an outage.
What efficiency should I use for AC devices?
Use 80% to 90% for most AC inverter loads unless you have measured data. The default calculator value is 85%.
Why should I measure with a watt meter?
Device labels are often maximum ratings. A watt meter shows real average draw and makes runtime estimates much more reliable.