Super Easy Energy Cost Calculator

How much energy does a light bulb use? Is it worth replacing? Those kind of answers can be found with this easy guide.

Find the light bulb wattage on the left hand side. Across the top find the hours per day it is used. Where that row and column meet is the cost of powering that light bulb for one year.

An old 75 Watt bulb running 5 hours a night costs $37 a year. Definitely worth changing to a more efficient option.

It also works for other items - if you know their power usage. A stereo that uses 10 Watts in standby mode all day will cost $24 a year even without playing any music (might be worth turning off at the wall). A laptop computer that uses 20 Watts and is used for 4 hours per day will cost just $8 to run.

For this calculator I've assumed 27 cents per unit of electricity. If your price is different then the estimates may vary.

Also, if the exact wattage isn't in the table, use one that is close to it as an estimate. Or if you've got a calculator you can do the exact calculations yourself. Here's the formula:

Cost = Watts x hours/day x 0.365 x price($/kWh)

Quiz: Are you a climate champ?

Take this quiz to find out how you score on your climate change knowledge.

It's been all over the news, but how much information has sunk in?

I aced it with 10 from 10 - but it is multiple choice so that makes it a bit easier.

Should I get solar?

It's a question that many people have asked. Australian consumer affairs TV show The Checkout took a look at at practically every solar question people ask.

Quirkiness is the trademark of the show, but the information is good.



Here's the link to the solar calculator they mention.

In case you missed it, here is the information on payback periods.