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Every factor states the unit it is measured against. Check it before you use the number - the basis is the most common way to get a confidently wrong answer. Livestock factors are per head per year, nitrogen fertiliser is per kilogram of nitrogen rather than product, and freight is per tonne-kilometre. Choose a factor to see its detail and convert a quantity.
| Factor | Unit | kg CO2e per unit |
|---|
Call it as an API
The same catalogue is available as a free, unauthenticated JSON API. There is no key to request and no rate card - it is published data, served cleanly. The daily market reference and the live listings (asking price and units available) are free in the same way: see Market Pulse.
Browse and search
Called bare it returns the browse taxonomy, the list of units in use, and the first page of factors. q narrows on every term, so bulk carrier 200 is more specific than bulk. Paginate with limit (200 max) and offset.
Convert a quantity
Returns kilograms and tonnes of CO2-equivalent, with the arithmetic shown. Pass the optional unit parameter and it is checked against the factor's own basis - a mismatch is refused rather than multiplied, because that is the error worth catching.
Electricity is a special case worth understanding
The Ministry publishes the New Zealand electricity factor per quarter as well as per year, and the quarterly values move a long way with hydrology. Across 2025 they ranged from 0.0273 to 0.1159 kg CO2e per kWh, against an annual average of 0.0787 - roughly a fourfold spread inside one year.
That means the period you pick matters more than almost any other choice in an electricity calculation, and an annual average can understate or overstate a quarter's consumption substantially. Use the factor for the period the electricity was actually used in.
What these factors are, and what they are not
They are national averages, published for voluntary organisational reporting. They are not measurements of your site, your vehicle or your herd, and the Ministry revises them every year - the agriculture numbers moved measurably between the 2025 and 2026 releases. A recognised programme or an assurance provider may require a different methodology.
This catalogue reproduces the published figures for reference and converts quantities using them. It does not price anything, and nothing here is financial, legal or tax advice. The authoritative source is the Ministry's own Measuring Emissions guide.
Where this fits
If you are a farmer, the farm emissions calculator applies the agriculture factors to your stock and fertiliser. If you have an ETS surrender obligation, the ETS obligations calculator uses the statutory factors instead of these - they are a different, legally mandated set. To keep a measured scope 1, 2 and 3 ledger built on this catalogue, see Carbon Tracker®.