Every New Zealand emission factor, in one place
The complete set of emission factors published by the Ministry for the Environment - 902 of them, across travel, freight, refrigerants, electricity, fuel, waste, water and agriculture. Search them here, or call the same data as an API. No account, no key, no charge.
Search the catalogue
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.
| 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.
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, My Farm applies the agriculture factors to your stock and fertiliser and keeps the profile in your account. If you have an ETS surrender obligation, My Obligations uses the statutory factors instead of these - they are a different, legally-mandated set. If you hold registered forest, My Forest tracks carbon accumulation against the MPI look-up tables.