WWF have a simple tool to give a visual image of your Carbon Footprint. It will ask questions about your lifestyle and then suggest how to start to reduce your Carbon Footprint.
Pawprint's tool is designed to engage employees within an organisation and get them to measure their footprint. You can download an app to your mobile phone to enable you to track your carbon emissions. It breaks down emissions by Home, Travel, Diet, Other and gives good tips on how to reduce your footprint, and log actions.