You don’t have to measure your carbon footprint in order to start reducing it but go on, admit it – you’re curious, aren’t you? You want to know just how much (or hopefully how little) an impact you’re having on the planet.

It’s a case where smaller really is more beautiful.

So how do you go about calculating your carbon footprint, when virtually everything you do creates carbon? You need to go through every little thing, and be thorough and honest, until you reach a final total. That includes what you spend on heating and running the appliances in your home, your car, every facet.

##### Your Home

For many of us, it’s gas that brings water and heat into the home. Look at the kilowatt hours (kwh) on each of the four quarterly bills for the last year, and add them up. To find out your total emissions, multiply the number of kilowatt hours by 0.19, then divide by the amount of adults in the house to discover the figure. If you’re not bothered about being completely exact, calculate 10,000 kwh for a small house, 20,500 for a medium-sized house, and 28,000 for a large house

For electricity you should also total the kilowatt hours used over a year, then multiply that figure by 0.43, and finally divide by the number of adults in the house. If the bills have vanished, try a rough total of 1,650 kwh for a small house, 3,300 kwh for a medium sized house, or 5,000 kwh for a large house.

##### Your Car

Figuring the carbon footprint for you car is a lot trickier, and any figure is going to be a guesstimate. So much depends on how far you drive, as well as how you drive, on top of the type of vehicle you own.

As a very general rule, any car will emit its own weight in carbon dioxide for every 6000 miles that you drive. So, first work out how many miles you drive each year. Divide this by 6000 to find out how many times its own weight of carbon dioxide your car produces in a year. Then you need to estimate the weight of your car, in kilograms.

A small car like a Fiat or a Renault Clio or a Golf will weigh about 1100 kg. A larger family car like a BMW or a large Rover or Mazda might weight around 1800 kg. And if you have a MPV or a Range Rover or a big, high vehicle like that that can take around 7 people, then your vehicle possible weighs around 2800 kg. If you want to make your calculation as accurate as possible, find the actual weight in your handbook or from your car manufacturer or from the internet. Search for the model name, the word weight and the word specification and hunt around. Some cars are heavier than you expect – a mini clubman S, for example, has a gross weight of 1690 kg.

Take the figure you have for the weight of your car and multiply it by the number you got by dividing your total annual mileage by 6000. This will give you an idea of the number of kilograms of carbon dioxide your car produces each year. Remember though, that this doesn’t take into account the carbon dioxide that was produced when it was manufactured. Your carbon output will also be higher in any car if you drive it very fast, or do a lot of stop-start journeys in heavy traffic.

##### Other Items

There are, of course, many other things in your life – your shopping, for instance, and it’s almost impossible to come up with a carbon total for that over the course of a year. Much of our food comes from abroad, meaning it has “food miles” attached to it – but did you buy strawberries 10 months ago? How would you remember?

Still, there are a few things you can calculate. Take your holiday, for instance. Where did you go? Did you fly there? If so, you can come up with a figure for the CO2 emissions on the flight. Maybe you went to Turkey, a very popular destination. If you did, that’s 1275 kg of carbon – per person each way. If you take two foreign holidays a year and fly, the figures soon add up. It can be very instructive to sit down and calculate your carbon footprint, and the chances are that you’ll be surprised at just how large it is. That knowledge can be an important first step in lowering it.

If maths isn’t your strongest point, don’t worry. There are a number of web sites where you can simply enter the figures and they’ll make the calculations for you. However you do it, it’s the results, and the determination to change things, that matter.