Mean and median pay measure different features of a pay distribution. The mean is the arithmetic average: add the relevant pay values and divide by the number of workers. The median is the middle pay level after values are ordered from lowest to highest. Directive (EU) 2023/970 defines median pay level and median gender pay gap and requires employers within scope to report both the gender pay gap and the median gender pay gap, as well as corresponding measures for complementary or variable components. The mean is more sensitive to very high or low pay values, while the median is less affected by extremes. Both should therefore be calculated consistently and interpreted together rather than selecting whichever produces the smaller gap.
Jurisdiction: European Union
The Mean Is the Arithmetic Average
To calculate mean pay, add the pay values for the workers included in the defined population and divide the total by the number of workers. The calculation is simple, but the result depends heavily on the input definition. Analysts need a consistent measurement period, pay concept and inclusion rule. A mean calculated from annual base salary should not be compared casually with another measure built from gross hourly total pay. National reporting methodology should control where it specifies the required basis. The mean is useful because it captures the value of every observation in the group, but that also makes it sensitive to extreme pay values.
The Median Is the Middle of the Ordered Distribution
The Directive defines median pay level as the pay level at which half of the workers earn more and half earn less. In practice, analysts order the relevant pay values from lowest to highest and identify the middle position, applying the appropriate convention when the population contains an even number of workers. Because the median depends on position rather than the magnitude of every value, a very highly paid individual can change the mean substantially without moving the median at all. That makes the median useful for describing the typical centre of a skewed pay distribution.
Mean and Median Can Tell Different Stories
Suppose one group has a small number of very highly paid workers while most employees are concentrated around the middle of the distribution. The mean can move upward because those high values contribute directly to the average, while the median may remain near the typical worker's pay level. The reverse can also occur when unusually low values pull the mean downward. A large difference between mean and median gaps can therefore indicate concentration at the top or bottom of the pay distribution, outliers or differences in workforce composition. It does not by itself identify the cause, but it tells analysts where to investigate further.
Article 9 Requires Both Perspectives
Article 9 requires the gender pay gap and the median gender pay gap. It also requires the gender pay gap and median gender pay gap in complementary or variable components. These are separate reporting outputs, not optional alternatives. Employers should therefore build the dataset and calculation process so both measures can be reproduced from the same governed population and component definitions. If national implementation supplies a prescribed formula, treatment of zero values or other detailed calculation rules, those instructions should be followed rather than replaced by an internal analytics convention.
Keep the Population and Pay Definition Consistent
A comparison becomes misleading when the mean and median are calculated from different worker populations or different pay definitions. Analysts should document which workers are included, the measurement period, whether the value is hourly or annual, how part-time arrangements are handled and which pay components are included. The same care is needed for complementary or variable pay because workers who receive no variable component can affect the interpretation depending on the reporting methodology. Consistency makes the results comparable across periods and easier to reconcile with published figures.
Use the Difference Between the Measures as a Diagnostic Signal
Mean and median should not be treated as competing statistics where one must be chosen as the more favourable result. Their difference is analytically useful. If the mean gap is much larger than the median gap, high-value observations or senior-role concentration may be influencing the average. If the median gap is larger, the central part of the distribution may show a broader structural difference even when extreme values offset part of the mean. Employers can then examine quartiles, worker categories, job levels and pay components to understand the pattern rather than stopping at the headline percentage.
Frequently Asked Questions
Which is better for pay analysis, mean or median?
Neither is universally better. They describe different features of the distribution, and the Directive requires both headline gender pay gap and median gender pay gap reporting for covered employers.
Why can the mean change more than the median?
The mean uses the magnitude of every value, so very high or low observations can move it significantly. The median is based on the middle position and is less sensitive to extreme values.
Can an employer report only the median because it is less affected by outliers?
No. Article 9 treats the gender pay gap and median gender pay gap as separate required metrics for employers within the reporting scope.
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Official Sources
Requirements and practices differ by jurisdiction and organisation. Check current local law, official guidance and professional advice for a specific situation.