Bristol RoadLindenGloucestershireGL1 5RZ

Power on Rent

Reliable Portable Generator Hire in Gloucestershire

Phone Number: 01172541059

What Size Generator Do I Need?

Do you need to find out what size generator you need for your wedding or big event? Finding a generator that will sustain all your power needs is a vital aspect when hiring one. Using a generator that cannot meet all your requirements is a terrible decision as it may damage all the devices connected to it or even the generator itself. Determining the size of generator you need may seem like a daunting task as there are several important considerations you have to think about.

Deciding on either a standby or motor generator, kW, kVA single-phase or three-phase generator can be challenging. To eliminate all this confusion, we've put together a brief guide that will help you understand how to select the size of a generator and what to consider.

If you are still unsure which generator will be able to handle all of your power needs, speak to us at 01172541059 and we will be more than happy to help.

generator set up for outdoor events

Generator Size Variation

Due to the advancements in the electrical and engineering fields, there is an extensive range in sizes of generators. Power on Rent have a versatile range of hire fleet of portable generators available for commercial and domestic uses. 

Though our generators are rated in kVA, we determine the requirement in kW and use that to calculate the most suitable generator for the job. The formula is thus follows:

Total requirements (kW) ÷ Power Factor (0.8 for almost all diesel generators) = kVA 

As an example: If we require 3000 Watts of power to be supplied at any one time, this means we require a 4 kVA generator.

More domestic examples include:

1800 Watts (2.4 kVa)

This is enough to power small devices around the home and ideal for short-term temporary power. The appliances that use up to 1000 watts include; toaster, jigsaw, TV, small fridge (dependent on the type) and handheld drills. 

3500 Watts (4.4 kVA)

Recommended for power tools that require up to 2200 watts. These include TV, microwave, air conditioning, oven, lighting, and small pumps. 

6000 Watts (7 kVA)

This is ideal for power devices that use around 3400 watts. These include washing machines, large TVs, heaters and cookers. 

Please note that every appliance requires extra wattage to start up, known as the Surge Watt. This will eventually drop to the Running Watt which is the level of energy required to keep the appliance running. Although you may have enough power from your generator to run several appliances, it's advisable that you stagger the start-ups so you don't risk oversurging the generator.


If you have any additional questions, please visit our FAQ section to see if your question is listed. Alternatively, please contact us via 01172541059 or use the contact form below to forward your query. All of our friendly team members are highly knowledgeable in this industry and will be more than happy to help.