Petrol vs Public Transport Calculator NZ
This calculator takes one commute and costs it three ways, so you can see what driving, taking public transport and cycling each cost you over a year and how long each one takes. Driving is costed on the Inland Revenue kilometre rates, which represent the full cost of running a vehicle rather than just the fuel in it, so the figure is larger than most people expect. Public transport is costed on the fare you actually pay, because fares are set by regional councils and operators and any table of them would be out of date somewhere in the country within months. Cycling is costed on what a bike really costs you across a year in servicing, parts, replacement and wet weather gear, which is small but is not nothing. Each mode also shows the hours a year it takes, because the cheapest option is frequently the slowest and that trade-off is the actual decision. One caveat that changes the answer more than any input: if you would own the car anyway, switching to the bus does not save you the whole running cost, only the fuel and wear of the trips you no longer make. There is a setting for that below.
| Mode | Cost a year | Hours a year | Cost a week |
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Driving is costed at the Inland Revenue kilometre rates for the 2025-26 income year. Commuting is private travel and is not tax deductible; the rates are used here only as a maintained estimate of what a kilometre costs to run.
How it works
Annual kilometres are your one-way distance times two, times days a week, times weeks a year. Driving costs those kilometres at the IRD tier one rate for your vehicle up to 14,000 kilometres and the tier two rate above it, then adds parking and tolls per day worked. If you would keep the car anyway, only the tier two rate is applied, because the fixed costs of owning the vehicle are being paid whether you commute in it or not and only the running cost of the trips is genuinely saved. Public transport is your one-way fare times two, times days worked. Cycling is the annual figure you enter. Hours for each mode are the one-way time times two, times days worked. Where you enter an hourly value for your time, it is applied to the difference in hours against the cheapest mode and reported separately.
Worked example
A 12 kilometre trip each way, five days a week, 46 weeks a year, in a petrol car. That is 5,520 kilometres a year at the tier one rate of $1.20, so driving costs about $6,624. A $3.50 fare each way is $7 a day over 230 days worked, about $1,610. A bike costing $400 a year is $400. Cycling is cheapest by a wide margin, and public transport saves about $5,014 a year against driving. On time, driving takes about 169 hours a year, the bus about 307 and the bike about 291, so the bus costs roughly 138 hours more than driving to save about $5,014, which works out at around $36 an hour of your time.
The thing that changes the answer
Whether the car exists anyway. If you are deciding between owning a car and not owning one, the full tier one rate is the right comparison and driving looks very expensive. If the car is in the driveway regardless, because of weekends, children or a second job, then switching your commute to the bus saves only the marginal running cost of those trips, and the honest comparison uses the tier two rate. That single setting moves the driving figure by roughly two thirds, which is more than any other input on this page.
Related calculators
- Commute cost calculator: what your current commute costs in full.
- Long commute vs a closer house: whether moving in is worth it.
- Is the job offer worth the travel: a pay rise against a longer trip.
- Vehicle running costs: the whole cost of the car.
- What your commute really costs: the background to this calculation.