# What is the False Omission Rate?

Given a *negative *prediction, the **False Omission Rate **(FDR) is the performance metric that tells you the probability that the true value is *positive*.

- It is closely related to the False Discovery Rate, which is completely analogous.
- The complement of the False Omission Rate is the Negative Predictive Value. Consequently, they add up to 1.
- The False Omission Rate answers the question:
**“If the prediction is negative, what share of my prediction is truly positive?”** - The False Omission Rate is calculated as follows:

\frac{FN}{FN+TN} = \frac{FN}{N} = FOR