Housing stress is a measure of people's incomes in proportion to their cost of housing, be it mortgage repayments or rental liabilities. It is a useful measure of social disadvantage than just relying on Gross Domestic Product, since housing is something indispensibly essential for physical and psychological well-being, something that will generally consume the largest component of personal expenditure, and is something that can vary tremendously in price due to geographic, demographic and economic factors.

Mass transport and mass production has made it possible for goods and services to be sold at prices that are relatively homogeneous in different parts of a country. However housing is a more fixed commodity, being traded an imperfect market with considerable time lags between when a shortage is first identified and when it is filled. Most obviously, supply and demand dictate the price of housing, and places where people want to live generally fetching premium prices. A paycheck of $600 a week may be good in rural Nebraska, but totally inadequate in New York City. Housing stress can also measure the impact of poverty on people whose rental costs are necessarily higher, such as families.

The Australian Bureau of Statistics define housing stress as being when the poorest 40% of people (excluding the poorest 10% for statistical relevancy purposes) pay more than 30% of their incomes on housing. Richer people may also be paying a large portion of their pay checks on housing, yet it is assumed these people can either choose to move to cheaper accomodation or forgo discretionary income to pay for increases in the weekly mortgage. In 2002-03, 6% of Australians were said to be in housing stress, split evenly between renters and mortgagees.