Calculators

Road user charges for an EV, diesel or plug-in hybrid

What a light vehicle pays in road user charges over a year.

Petrol vehicles pay for the road invisibly, through excise at the pump. Diesels, EVs and plug-in hybrids pay little or no excise and buy road user charges instead, in prepaid 1,000 km blocks, which is why the bill feels like a new tax rather than the same tax collected differently. petrol_equivalent_excise is there to make that comparison directly.

The transaction fee is the part a naive calculation misses. RUC is bought in blocks and every purchase carries a fee, so 20,000 km bought in 1,000 km blocks pays it twenty times. Buying larger blocks is the main lever a driver has, and transactions and admin_total make it visible.

A PETROL plug-in hybrid pays roughly half, because it already pays excise on the petrol side. A DIESEL plug-in hybrid pays the full rate, because diesel carries no excise. That catches people out.

An ordinary petrol hybrid pays NO road user charges. It is not exempt: it pays at the pump like any other petrol vehicle, and the response says so.

Light vehicles 3,500 kg and under only. Heavy vehicle rates run to dozens of weight and axle combinations and are not here. provenance says which figures are confirmed against NZTA: the rate is, the fees are not.

post/v1/road-user-charges

Request

  • Base URL: https://api.calculate.co.nz
  • URL: https://api.calculate.co.nz/v1/road-user-charges
  • Auth: API key in header X-API-Key

Request body

annual_kmnumber required

Distance driven in a year.

vehicle_typestring

ev, diesel, phev_petrol, phev_diesel or hybrid_petrol. A PETROL plug-in hybrid pays about half; a DIESEL one pays the full rate. An ordinary petrol hybrid pays no RUC at all.

block_size_kmnumber

Size of each RUC purchase. Larger blocks mean fewer transaction fees, which is the main lever a driver has.

purchase_methodstring

online or agent. The transaction fee differs.

fuel_efficiency_l_per_100kmnumber

Used only for the petrol excise comparison, never for the RUC itself.

Example request

{
  "annual_km": 11500,
  "block_size_km": 5000,
  "fuel_efficiency_l_per_100km": 8,
  "purchase_method": "online",
  "vehicle_type": "diesel"
}

Response

The annual charge, the transaction fees, and what a petrol driver pays instead.

disclaimerstring required

Scope and limits of this calculation.

Example response

{
  "disclaimer": "Indicative. Light vehicles 3,500 kg and under at NZTA rates confirmed 29 August 2026; heavy vehicle rates run to over a hundred type and weight combinations and are not covered here.",
  "result": {
    "admin_fee_each": 12.44,
    "admin_total": 37.32,
    "annual_km": 11500,
    "block_size_km": 5000,
    "cost_per_km_cents": 7.92,
    "difference_against_petrol": 267.32,
    "fuel_efficiency_l_per_100km": 8,
    "note": "Bought in 5,000 km blocks, that is 3 transaction(s) a year at 12.44 each. Larger blocks mean fewer fees.",
    "pays_ruc": true,
    "petrol_equivalent_excise": 644,
    "provenance": {
      "petrol_excise_per_litre": "0.70, used only for the comparison figure, not for any RUC amount",
      "ruc_rate": "NZ Transport Agency, light vehicles 3,500 kg and under, confirmed 29 August 2026",
      "transaction_fees": "NZ Transport Agency, confirmed 29 August 2026: $12.44 online or through the NZTA app, $13.71 at an agent counter"
    },
    "ruc_charge": 874,
    "ruc_rate_per_1000km": 76,
    "tax_year": "2026/27",
    "total_annual_cost": 911.32,
    "transactions": 3,
    "vehicle_label": "Light diesel, under 3,500 kg",
    "vehicle_type": "diesel"
  }
}

Changes

No recorded changes to this operation across all 1 revision of this API.