Use our Backup Power Calculator UK to estimate the power output and battery capacity you need during a power cut. Select the appliances you want to keep running and get a practical backup power requirement based on your needs.
GRIDRESOLVE BACKUP POWER CALCULATOR
What needs to keep running?
Select the appliances that matter during a power cut. GridResolve applies typical cycling and short-use allowances automatically. You can replace our wattage figures with the rating from your own appliance.
Add something else
Custom appliances are treated as running for the full backup period unless you enter a shorter number of hours.
YOUR RESULT
Your backup power requirement
Best-fit backup approach
Suitable options
These products meet or exceed the calculated requirement based on the specifications stored by GridResolve.
Some product links may be affiliate links. This does not change the price you pay.
Your selected loads
Want to keep your results? Please print or write them down — GridResolve does not collect or store calculator data.
How GridResolve sizes it: continuous loads are added together, the single largest additional startup surge is added, then output headroom is applied. Battery capacity includes typical appliance cycling plus inverter/conversion losses and a reserve. Appliance labels and real-world consumption vary, so check manufacturer specifications before buying or connecting backup equipment.