Carbon calculators

Catalyst has developed two carbon calculators - the ACE Carbon Calculator and the Marine Freight calculator. Each is free to use, just click on the links in the Tool Box on the right to be taken to them.

ACE was designed to help you estimate the greenhouse gas (GHG) emissions arising from your household or business activity, working on the theory that "you cannot manage what you cannot measure".

Once you have measured your emissions you are in a strong position to manage them through reducing them where you can and offsetting some or all of the remainder. There are a number of ways to reduce emissions.

New Zealand and Australian versions are available. Please ensure you download the version relevant to you. This is important as different data is used in each country.

Activities for input into ACE include:

  • Electricity usage
  • Gas consumption
  • Coal consumption
  • Petrol consumption
  • Diesel consumption
  • LPG consumption
  • Waste disposal
  • Taxi travel
  • Airline travel
  • Refrigerant data
  • Materials data


For more information on ACE click here.

Carbon calculators toolbox


ACE Carbon Calculator

A downloadable Excel based tool that measures the GHG emissions of businesses and households.

First time users register here.

Registered users login here.

ACE Support Package

Need on-demand assistance with using ACE or any other environmental footprinting work? Our 12 month Support Package may be just the thing. Click here for details.

Marine Freight Calculator

An online calculator that measures emissions associated with container sea freight.

Click here to be taken to it.

Who is using ACE?

Over 1000 individuals or companies have used ACE in the past 10 years to measure and manage their GHG emissions. Users include:

  • The Sustainable Business Network
  • Trevelyans Pack & Cool Ltd
  • Scion
  • AgResearch
  • University of Waikato
  • Tauranga City Council


"Hi there, I've just stumbled across your ACE 2010 tool. I think this is an outstanding example of people who have a real self sacrificing spirit. The fact that you developed this tool is great. But making it available to others at no cost is truly a selfless gesture. Good on you guys. We're just starting out on the road to "Sustainability" so we really appreciate all the help we can get."

Peter Dewstow,
CNC Supervisor,
Espies NZ Ltd