How much is that daily commute really costing you?

A new data-crunching interactive map enables Auckland and Wellington renters to see just how affordable their living situation is when transport costs are factored in.

Echoing the findings of a study published earlier this year, the interactive graphic Affordable New Zealand found the cities' outlying suburbs may not be as affordable as people believe after transport is added to the bill.

The Herald created a fictional Auckland renter, earning $65,000 a year, driving to work in the city and looking for a three-bedroom rental.

With petrol, car and parking costs factored in, total living costs for some inner-city areas appeared as affordable and in cases cheaper than outer suburbs such as Albany and Fairview Heights.

Renting in Pukekohe North cost 45.6 per cent of the renter's weekly income - almost exactly that as in Point Chevalier South, according the map.

Because peak hour data was not included, the map did not reflect the time commuters waited in traffic each day and therefore true transport costs and time for renters in outer areas were likely to be much higher.

Dr Alex Raichev, of transport consultants MRCagney, was inspired to create the map after seeing a rent versus income graphic for London in the Financial Times.

When a new Auckland affordability study reflecting transport costs was published in scientific journal Cities this year, Dr Raichev factored these in and noted the difference.

"If I hadn't read that paper, I would have been surprised at how unaffordable the outlying suburbs become if you factor in parking and commute costs."

While Dr Raichev said the paper was important for policymakers, the map he developed with colleague Saeid Adli was more useful for renters to get a sense of where they might get a better deal.

"I hope public policy makers are really thinking about this issue, because these are big chunks of money that should be incorporated."

Dr Raichev wanted to further develop the map by factoring in house prices, multiple commuters and peak traffic factors.

Kerry Mattingly, who co-authored the Cities paper, was pleased to see parts of his research had been used to create the website.

"Unlike housing, it's often difficult to calculate the cost of commuting," he said.

"This will be a truly useful tool for households wanting to better estimate and compare the affordability of different locations around Auckland and Wellington."

Auckland transport commentator Matt Lowrie said transport and housing costs had to be considered together to "really understand" the affordability of a location.

"Often, housing costs alone get mentioned, particularly by advocates of growing the city through sprawl," he said.

"Ignoring the transport costs of spreading outwards is either lazy or deliberately deceptive so it's important to have tools such as this to get a broader picture."

* Take a look at the map here.