The calculator
We have built the Google UK Carbon Calculator in partnership with the Energy Saving Trust and RSA. It uses the AMEE engine, and draws on the UK Government's Act on CO2 calculator for its data, calculations and approved methodologies.
Carbon calculator questions
Below you'll find the questions we'll ask you when you fill in the carbon calculator, the reasons we're asking them and some additional information to help you get an accurate number.
| Questions: Your home | Why we're asking | Information | |
| What kind of property do you live in? | This affects how much heat the property needs and what actions you can take to make your home more efficient. | ||
| What's your postcode? | We'll use this to put you on the map once you've calculated your footprint. (You can then move the pin to where you live on the map, or leave it where it is if you prefer not to show the exact location of your home.) | ||
| When was your home built? | This can affect how much heat the property needs and what actions you can take to make your home more efficient. | ||
| How many bedrooms do you have? | We'll use this to estimate the size of your house and hence your heating needs. | Include spare rooms and studies | |
| How many people live in your home? | We'll divide your household carbon footprint by this number to calculate your personal individual footprint. | ||
| Which of the following do you have? - Cavity wall insulation - Loft insulation - Double glazing |
This can affect how much heat the property loses and what actions you can take to make your home more efficient. | Cavity wall: Filling the gap between the two walls of a house with an insulating material massively decreases the amount of heat which escapes through the walls. It will help create a more even temperature in your home, help prevent condensation on the walls and ceilings and can also reduce the amount of heat building up inside your home during summer hot spells.
Loft insulation: Without loft insulation you could be losing as much as 15% of your heating costs through your roof. Insulating your loft is a simple and effective way to reduce your heating bills and you can even do it yourself. Loft insulation acts as a blanket, trapping heat rising from the house below. You should also consider lagging your pipes at the same time for optimum efficiency. Double Glazing: Double glazing works by trapping air between two panes of glass creating an insulating barrier that reduces heat loss, noise and condensation. Double glazing cuts heat lost through windows by half. |
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| What's the main heating source for your home? | There are different carbon footprints associated with different heating fuels – some are less polluting than others. | ||
| How much is your annual heating bill? Completing this will make your carbon footprint much more accurate since heating is a major contributor. | This tells us how much energy you use and allows us to accurately calculate your heating footprint. If you don't have your bill to hand then the calculator will estimate your heating footprint based on the size and age of your house. | If you pay monthly by direct debit, multiply the monthly cost by 12. If you pay quarterly, remember that your heating bill is very different in summer and winter. If your most recent bill is a spring or summer bill, multiply it by 7.7 to get your annual total. If it is an autumn or winter bill, multiply it by 2.7. If you don't have a bill to hand now, please estimate your annual cost. You can come back and update this with a more accurate value later. |
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| How much is your annual electricity bill? | This tells us how much electricity you use for powering your appliances and gadgets. | If you pay by monthly direct debit, multiply the monthly cost by 12. If you pay quarterly, remember that your heating bill will be different in summer and winter... ...If you heat you home using electric heating and your most recent electricity bill is a spring or summer bill, multiply the bill by 4.8 to get your annual total. If it is an autumn or winter bill, multiply it by 3.5. ...If you don't heat your home using electric heating and your most recent electricity bill is a spring or summer bill, multiply it by 4.2 to get your annual total. If it is an autumn or winter bill, multiply it by 3.9. If you don't have a bill to hand now, please estimate your annual cost. You can come back and update this with a more accurate value later. |
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| How many of your lightbulbs are energy efficient? | An energy efficient lightbulb uses a fifth of the energy of a standard lightbulb. | These bulbs are otherwise known as CFLs – compact fluorescent lamps. | |
| How many of your appliances (dishwasher, washing machine, fridge, tumble dryer) are energy efficient? | Energy efficient appliances use less power every time you use them, saving you CO2 and money. | Are your appliances A or A+ rated? Full list of recommended appliances |
Actions
When you complete the carbon calculator we will recommend actions that are personal to you, based on your answers to the questions. As you complete your actions you can go back and tick them off to automatically update your carbon footprint.
| Recommended Actions | More information | |
| Install cavity wall insulation. | Filling the gap between the two walls of a house with an insulating material massively decreases the amount of heat which escapes through the walls. It will help create a more even temperature in your home, help prevent condensation on the walls and ceilings and can also reduce the amount of heat building up inside your home during summer hot spells. | |
| Install loft insulation. | Without loft insulation you could be losing as much as 15% of your heating costs through your roof. Insulating your loft is a simple and effective way to reduce your heating bills and you can even do it yourself. Loft insulation acts as a blanket, trapping heat rising from the house below. You should also consider lagging your pipes at the same time for optimum efficiency. | |
| Install double glazing. | Double glazing works by trapping air between two panes of glass creating an insulating barrier that reduces heat loss, noise and condensation. Double glazing cuts heat lost through windows by half. | |
| Switch to energy-efficient light bulbs throughout your home. | This will save energy and cut your electricity bills. | |
| Upgrade to energy-efficient appliances throughout your home. | Full list of recommended appliances | |
| Fill your kettle with only as much water as you need. | Boiling more water than you need for a cup of tea wastes energy and time. | |
| Wash clothes at 30 degrees. | Most 'worn once' or lightly soiled clothes will be adequately cleaned by a 30 degree wash cycle. | |
| Fill your washing machine to capacity. | This will save energy and your clothes will be just as clean. | |
| Air dry clothes more instead of using the tumble drier. | This will save energy and cut your electricity bills. | |
| Lower your thermostat by 1 degree. | This should reduce your heating bill by about 10%. | |
| Turn off the light when you leave a room. | This will save energy and cut your electricity bills. | |
| Turn your appliances completely off (not on standby). | Leaving appliances on standby wastes energy. You will be able to save between 5 – 10% on your electricity bill. | |
| Unplug mobile phone and other chargers when you're not using them. | Chargers use energy whenever they're plugged in. | |
| Turn down your TV display brightness. | Manufacturers set them to their brightest levels for display in showrooms. Turning it down will save electricity. | |
| Replace your desktop computer with a laptop. | Laptops generally use only 30% of the energy of a desktop computer. | |
| Defrost your freezer at least once a year. | This will keep it working as efficiently as possible. | |
| Use the microwave for reheating and light cooking. | Using the microwave is more energy efficient than the oven. | |
| Install a hot water jacket. | Insulating your hot water cylinder is one of the simplest and easiest ways to save energy and money. Fitting a 'jacket' around your cylinder will cut heat loss by over 75%. If you already have a jacket fitted, check that it's at least 75mm thick. If not, it's well worth treating your old cylinder to a new winter coat. | |
| Switch to a high-efficiency boiler. | If your boiler is 12-15 years old it might need replacing. ESR boilers are the most efficient. | |
| Invest in renewable energy technologies, such as solar hot water and wind turbines. | This will lower bills and cut carbon emissions. Make sure your home is as energy efficient as it can be before investing in these technologies. | |
| Use public transport for local trips where possible. | Using public transport instead of your car typically reduces journey related emissions by half. Moreover, on short journeys, a car's engine often doesn't get a chance to warm up therefore decreasing its efficiency and emitting even more CO2 than normal. | |
| Make your next car as clean as possible by choosing one of the most efficient in its class. | Manuals are more efficient than automatics and diesels are more efficient than petrol engines. | |
| Adjust tyre pressure, gear, and driving style to use less fuel. | This will save energy and cut your fuel costs. | |
| Walk or cycle for journeys less than 1 mile. | A car journey of less than 1 mile is the most inefficient type of journey as the engine does not have time to warm up properly and hence burns more fuel. | |
| When you can, take the train instead of flying. | Flying emits more than twice as much CO2 as trains. |
Methodology
The Google UK Carbon Calculator uses the same methodology, data and assumptions that have been used by the Government in their Act on CO2 calculator.
The calculator estimates individual carbon footprints based on a range of inputs. These include the approximate age, type and size of your home together with heating and electricity bills and details of energy saving measures such as insulation that have been installed. If you don't have energy bill data to hand, don't worry. A set of default values will be used in a similar way to in the Government's calculator.
The CO2 emissions from travel make up a significant proportion of individuals' carbon footprints. The calculator estimates the impact of your personal travel by allowing you to input the number and type of flights taken as well as the type of vehicle owned and annual distance travelled. These inputs are then used with official factors to calculate an estimate of your overall personal carbon footprint.
The calculator also provides recommendations to help you to reduce your carbon footprint. You can choose to do any number of these actions and see what impact they can make. These actions have been developed with the Energy Saving Trust, an independent, non-profit making organisation that provides impartial information and advice specifically designed to help people take action to save energy and carbon