Quick Offset Carbon Calculations
Carbon dioxide (CO2) is a greenhouse gas (GHG) which, when released into the atmosphere, acts like a thickening blanket, trapping the sun’s heat. If you already know your carbon footprint in tonnes of CO2 then there is no need to wait. You can offset your emissions online now. You can choose between Standard Offsets and Premium Offsets for as little as £3.50 per tonne! Go Carbon Free NOW and help preserve our planet.
Assumptions
The Quick Offset is designed to make offsetting your emissions easy and simple, while being as precise as is practical within the limitations of collecting carbon emissions data and using ‘average’ calculations.
Please find below a summary of how your emissions are calculated. Our price to offset one tonne of CO2 is £3.50 for our standard offsets and £6 for our premium offsets. The total price of our activity is based on the cost per tonne multiplied by the emissions generated by the particular activity. Where the total amount is an uneven value we have rounded up or down to the nearest half £.
Average Individual Emissions (one person, one year)
Average individual emissions are calculated from your lifestyle: heating and lighting your home, cooking, how energy efficient you are, etc. Figures are taken from the latest published figures of the United Nations Development Programme’s Human Development Report (UNDP, HDR) and the World Resources Institute’s Climate Analysis Indicators Tool (WRI, CAIT) for developed nations. The latest carbon emission data relates to 2004. Countries include the European Union 25, USA, Canada, Australia, New Zealand, Japan, Korea and Russia.
The figure arrived at is 9.7 metric tonnes CO2 / person / annum.
The family offset figure is simply 9.7 metric tonnes CO2 multiplied by the number of people in your family.
Resources:
UNDP: http://hdr.undp.org/en/statistics/data/climatechange/map/co2capita/
WRI: http://cait.wri.org/
Vehicle Emissions
Our vehicle emissions are based on the most up to date data from the UK government and represent a fair average for developed country car emissions for a variety of car types. According to UK Government’s Department for Transport the average annual distance traveled by a 4-wheel passenger vehicle is 19,300km (excluding vans). For our calculations we have multiplied the average mileage by the CO2 figure per km for each class of vehicle.
Vehicle Variations
| Vehicle Type |
Size (Label) |
Engine Size (L) |
g CO2 per km |
| Petrol Car |
Small |
< 1.4 |
180.9 |
| |
Medium |
1.4 - 2.0 |
213.9 |
| |
Large |
> 2.01 |
295.8 |
| Hybrid Car |
Medium |
N/A |
126.2 |
| |
Large |
N/A |
224 |
| Diesel Car |
Small |
<1.71 |
151.3 |
| |
Medium |
1.7 - 2.0 |
188.1 |
| |
Large |
> 2.01 |
258 |
Resources:
Guidelines to Defras GHG Conversion Factors Methodology Paper for Transport Emission Factors.
Figures available here: www.dft.gov.uk
Flight Emissions
Figures are based on the upper limit of the category distances. While you may not travel the full distance, the figure covers most eventualities. These guidelines keep the assumptions easy to use and establish a useful reference point. It is worth bearing in mind that shorter flights are less fuel efficient than longer flights as more fuel is burnt at take off.
Category Distances
Short haul: up to 1,000 miles, one way, e.g. intra-European flights, London - Madrid. For our calculations we have used 800 miles as the reference point. Estimated CO2 emissions of 20kg

Medium haul: up to 4,000 miles, one way, e.g. London - Dubai or New York - Los Angeles at 3,400 and 2,500 miles one way respectively. For our calculations we have used 3,000 miles as the reference point. Estimated CO2 emissions of 58kg
Long haul: above 4,000 miles, one way, e.g. London - Singapore or Tokyo - New York. For our calculations we have used 6,000 miles as the reference point. Estimated CO2 emissions of 1.1 tons
The emissions factor for medium haul flights was derived using an assumed distance of 1600 km and the following formulae.
X+500y =.15*500 for short haul
X+5000y=.11*5000 for long haul
Therefore our calculations are as follows:
Emissions factor kg/km (multiplied by) Miles, denoted by type of flight, giving us the total emissions in terms of kgs.
Resources:
Short Haul and Long Haul Flights: Our figures for emissions based on distance in terms of CO2 emission factor kg/km are provided by UK DEFRA (Table 9, Annexes to Guidelines for Company Reporting on Greenhouse Gas Emissions, updated July 2008).
Medium Haul Flights: The emissions factor for medium haul flights comes from the World Resources Institute GHG Protocol.
Carbon Life Credit
In the developed world the average person’s carbon dioxide emissions are almost 10 metric tonnes per year. This is called a carbon footprint and comes mainly from household energy usage and transport requirements such as car travel, flights and commuter transport.
We have assumed the average person's remaining years of life to be 40 years. As such, we estimate a person’s lifetime emissions to be approximately 387 tonnes.
Resources:
Our personal emissions rates are based on the latest published figures of the United Nations Development Programmes Human Development Report (UNDP, HDR) and the World Resources Institutes Climate Analysis Indicators Tool (WRI, CAIT) for developed nations.
Our sequestration information has been provided by the Asian Institute of Technology Forestry Department.
Personalised Carbon Emissions Calculations
The quick offsets we provide are fair estimates of various activity based on average emissions within the developed world. However, we acknowledge that sometimes it is important to know the precise carbon footprint of a particular activity based on its individual variables. As such, we are happy to undertake an individual calculation for you on request. Please CONTACT one of our carbon consultants if you require a tailor-made carbon calculation.