p50

p50 is a term used in statistics, finance, and energy forecasting. It generally denotes the 50th percentile, also called the median: the value below which half of observed data fall.

In statistics, p50 is computed by ordering observations and selecting the middle value; with an even sample size, it is typically the average of the two central values.

In probabilistic forecasting and risk assessment, p50 refers to a median scenario: the forecast that has a 50% chance of being exceeded. It is commonly used alongside other percentile-based targets, such as p90 or p95, to describe a distribution of possible outcomes.

Applications appear in energy production planning (for wind and solar), where a p50 forecast represents the median annual production; p90 or p95 indicate more conservative projections.

In project cost estimation and financial planning, a p50 cost is the median expected expenditure, representing a central estimate used for budgeting; higher-percentile values indicate higher confidence in meeting the forecast.

Because the 50th percentile depends on the underlying distribution, p50 may differ from the mean in skewed data and is frequently preferred when robustness to outliers is desired.