Generator fuel cost calculator

What your generator really costs per day, month and year.

A few litres a night does not feel like much until you add it up. Enter how much fuel your generator uses and how long you run it, and see the cost per day, week, month and year, next to a grid bill or solar repayment if you like.

Why use it

See the true yearly cost of running a generator, not just tonight's top-up.
Compare it with a grid bill or a solar repayment before deciding where your money goes.
Check what cutting an hour a day, or a fuel price change, does to your budget.

How it works

Enter how many litres your generator uses per hour.
Add the hours you run it per day and the days per month.
Enter the current price per litre.
Read the cost per day, week, month and year, and compare with an alternative if you add one.

Good to know

Never run a generator indoors, in a garage, or near doors and windows. Its exhaust contains carbon monoxide, which has no colour or smell and can kill.
Fuel use depends heavily on load. The same generator powering a few bulbs uses less than when it is running an air conditioner, so measure at your normal load.
Servicing and repairs are real costs too. Add a monthly allowance for oil and maintenance to see the full picture.

Questions

How many litres does my generator use per hour?

It depends on the model, its size, its age and how much you are powering. The manual often gives a figure. The most reliable way is to measure: fill the tank, run it for an hour at your normal load, and see how much it takes to refill.

Is solar cheaper than a generator?

It depends on your usage, local prices and the system you are offered. Enter the monthly repayment or cost as the alternative and compare it with your monthly fuel cost here, remembering that generators also need servicing.

Is it safe to run a generator near the house?

Keep it outdoors, well away from doors, windows and vents, so exhaust cannot drift inside. Carbon monoxide is invisible and has no smell. A carbon monoxide alarm indoors is a sensible extra precaution.

Are my numbers stored?

Only on your own device, so your figures are there next time. Nothing you type is sent to us.

Please note

Provided free, as is, for general use. It is not financial, engineering or safety advice. Results are estimates based on the figures you enter; real fuel use varies with load, model, age and maintenance, and prices change. Follow the manufacturer's instructions and local safety rules for installing and running any generator.