Portable Power Station Runtime Calculator

Use this calculator to estimate how long a portable power station will run your devices. Choose the battery capacity, tick the devices you want to power and read the estimated runtime and an output check.

How the calculator works

The estimate uses a simple formula: runtime (hours) = capacity (Wh) x efficiency / total load (W). Efficiency allows for conversion losses; 80-85% is a sensible estimate for AC devices. The output check compares your total load with the power station’s rated continuous output.

Limits to remember

• Devices with motors, such as refrigerators, need extra power to start. Check the surge rating.
• Cold weather and battery age reduce usable capacity.
• The power station itself uses some power, especially with the AC output on.
• Device wattages vary. Check the labels on your own equipment.

Not sure what size you need? Read what size portable power station do I need and how long a 1000Wh power station will last.

Frequently asked questions

Why is my real runtime shorter than the estimate?

Conversion losses, cold temperatures, start-up surges and the unit’s own power use all reduce runtime. Lowering the efficiency slider gives a more cautious estimate.

Can I use this for solar charging time?

This tool covers discharge runtime. See how many solar panels to charge a power station for charging maths.

About the author