# Grøn ejerafgift — Denmark car tax

Source page: https://valem.run/calculators/denmark/car-tax

Denmark's green ownership tax is based on fuel efficiency in km per litre — thirstier cars pay much more.

**Tax year:** 2026

## How it is calculated

Denmark's recurring car tax (gron ejerafgift) rewards efficiency: it is based on how many kilometres the car does per litre, so an economical car pays little and a thirsty one pays a lot.

Diesels carry an equalisation surcharge, and cars registered from mid-2021 use a CO2-based scale. Illustrative rates. Estimate, not tax advice.

## Worked example

With Brændstoføkonomi of 18, this model computes Årlig afgift of 800 DKK.

## Inputs

| Name | Label | Type |
| --- | --- | --- |
| `kmPerL` | Brændstoføkonomi (km/l) | number |

## Sources

- [Motorstyrelsen](https://motorst.dk) (checked 2026-08-02)

## What this page claims

The Valem engine reproduces this model's formula through 2 self-test cases. That shows internal consistency, not that the formula matches current law; the cited sources are the evidence for that. Estimate, not tax advice.

## For agents

- Model manifest (formula, constants, test vectors): https://valem.run/calculators/denmark/car-tax.json
- Compute by URL: https://valem.run/calculators/denmark/car-tax.json?kmPerL=18
- MCP: https://valem.run/mcp/calculators (call `calculate` with calculator `denmark/car-tax`)