Backup Power Calculator UK
Estimate the right portable power station for your home, essentials or off-grid setup during a UK power cut.
Add Wi-Fi, lighting, laptops, fridge use or your own appliance setup.
See peak watts, estimated energy use and a sensible battery-size buffer.
Use the result to avoid under-buying or jumping straight into more capacity than you need.
Whether you’re preparing for a power cut, protecting your home office, or planning off-grid use, this calculator helps you estimate the right portable power station for your needs in a simple, practical way.
What do you need backup power for?
Choose the devices you want to keep running
Not sure what to include? See what a portable power station can realistically run in a UK home →
Looking for a lighter setup? See what a 1000W power station is best suited to →
Tip: choose a common appliance to auto-fill the fields, or enter your own setup manually.
Your estimated backup power requirement
Your recommended power station and alternatives
warranty details confirmed per product · 30-day returns · UK-focused backup power guidance
Please note: Calculator results are estimates based on typical appliance usage. Actual performance may vary depending on appliance surge demand, battery condition, temperature, charging method and usage pattern.
Backup Power Calculator FAQs
What size power station do I need for a fridge?
That depends on the fridge type, running wattage, startup surge, and how long you want it powered. A modern fridge may use relatively modest running power, but runtime requirements make a big difference. This calculator helps estimate both output and battery size more realistically.
What is the difference between W and Wh?
W stands for watts, which measures how much power an appliance needs at a given moment. Wh stands for watt-hours, which measures how much energy is needed over time. In simple terms, watts tell you what a device draws, while watt-hours tell you how long a power station can support it.
Can a portable power station run a kettle?
Some can, but kettles usually need very high output for a short period. That means the power station must have enough inverter output, not just enough battery capacity. If you plan to run high-draw appliances like kettles, microwaves, or heaters, focus closely on the output requirement shown in your results.
How accurate is this backup power calculator?
It is designed as a practical planning tool rather than a lab-grade measurement. It uses typical usage assumptions and adds a sensible buffer to help you choose a setup that feels more reliable in real-world use. For unusual appliances or more demanding setups, it is always worth checking the product label or speaking with us directly.
What if I want longer runtime or solar charging?
If you want more flexibility, longer outage coverage, or partial off-grid use, you may be better suited to a larger-capacity model or a solar-compatible setup. The calculator gives you a strong starting point, and from there you can compare upgraded options based on runtime, charging speed, and expandability.