The median household income has risen 8.5 per cent over the past three years or just 1.5 per cent more than consumer prices.
Average household income from regular sources rose 11.5 per cent to $85,000. It is higher than the median income of $68,600 - where as many are higher as lower - because of the influence of higher-income households.
Average household expenditure rose 9.1 per cent over the three years, or 2.1 per cent after inflation.
Spending on transport rose 21 per cent, rents 9.1 per cent, spending on food 8.4 per cent and power bills 7.3 per cent.
The figures come from the household economic survey Statistics New Zealand conducts every three years, which surveys households' incomes and spending, including housing costs.
The largest source of household income - wages and salaries - rose 13.8 per cent to $64,000 on average over the past three years. At the median the increase was 9.5 per cent to $52,000.
Housing costs consume a larger share of the income of tenants than of owner-occupiers (who include those who have paid off their mortgages).
The survey found 23.1 per cent of households that rent paid out 40 per cent of their income or more in housing costs compared with just 5.6 per cent of owner-occupiers. Housing costs include rent, mortgage payments, local body rates and dwelling-related insurance.
Over the past three years the average rent has risen $33 a week to $275, an increase of 13.7 per cent.
But over the same period the average mortgage payment barely increased, just 1.1 per cent to $356 a week, reflecting a drop in interest costs in 2011/12, while rates went up 22 per cent and insurance 38 per cent.
The average household spent $49 a week on petrol in 2012/13, up from $40.80 three years earlier. That mirrors a rise in petrol prices as recorded by the consumers price index, which rose 23 per cent over the same three years.
Spending on the purchase of new cars rose 52 per cent and secondhand cars 21 per cent.
In addition, one randomly selected person over 18 in every household surveyed was asked about how satisfied they were with their lives and how adequately their income met their everyday needs.
A large majority - 76 per cent - said they were satisfied or very satisfied and 9 per cent said they were dissatisfied or very dis-satisfied. The other 15 per cent said neither.
Forty-three per cent said their income was just enough or not enough to meet their everyday needs, for accommodation, food, clothing, and other necessities.
Where household income was in the lowest fifth of the population, 64 per cent of respondents said their income was not enough or only just enough to meet their everyday needs.
But even where household income was in the highest fifth of the population by that measure, 20 per cent of respondents said their income was not enough or only just enough to meet their everyday needs.