The size generator you need depends on the appliances or equipment you want to run, along with their running wattage and startup wattage. Our calculator helps give you a guide based on the items selected.

To calculate generator size, add together the running watts of the appliances you want to use, then allow for the highest startup wattage. It is also a good idea to include a safety margin to avoid overloading the generator.

Running watts are the power needed to keep an appliance operating. Starting watts are the extra power needed when an appliance first starts, especially equipment with motors such as pumps, compressors and fridges.

Yes, many generators can run a fridge and freezer, but you need to allow for startup wattage as well as running wattage. A small inverter generator may suit light home backup, depending on what else you need to run at the same time.

Inverter generators are often a popular option for home backup power because they are quieter and provide stable power for sensitive electronics. The best option depends on how many appliances you want to run at once.

Yes — this calculator is a guide only. Actual power requirements can vary depending on the appliance, startup load and how it is used. If you are unsure, contact our team and we can help recommend the right generator.