Median income is the exact middle income earned by someone in a job or career field. Average income is the mathematical mean of all incomes for that position. In most cases, these income levels are very close, though especially high or low salaries can cause the average to be higher or lower than the median income.
Median Income Overview
The median income is the amount normally given in response to the question, "What is the typical income for a position?" In math, median is the exact middle of a set of numbers. If there are 3,999 items included in a set of salaries being evaluated, the median salary is the one that is ranked 2,000th. There are exactly 1,999 people with higher salaries and 1,999 people with lower salaries. Median income is the salary calculation used to identify Americans as either lower, middle or upper class.
Average Income Overview
Average income is derived using the mathematical formula for mean or average. To identify the average income for a population group or career field, add together all incomes included in the assessment, then divide by the number of items. If the income of 100 people in a field combined total $5 million, for instance, divide $5 million by 100 to get the average. In this case, the average income of the group is $50,000.
Career Field Examples
The U.S. Bureau of Labor Statistics publishes annual data on both median and average income for many career fields. As of May 2014, family and general practitioners had a median income of $180,180, and an average annual income of $186,320. This income discrepancy could occur because many of the lower salaries are just below the median, many of the top salaries are well above the median, or a combination of the two.
Social workers had much closer median and average income levels as of May 2014. The median income level was $59,100, and the average income was $58,410. In contrast to doctors, social workers had an average income below the median. However, the closeness of these numbers gives a clearer picture of the normal or typical income earned in this position.
The BLS also provides data on income at the 10th, 25th, 75th and 90th percentile levels of all salaries. Entry-level employees usually earn incomes at the lower percentile ranks.