Diminution in value is a legal term of art used when calculating damages in a legal dispute, and describes a measure of value lost due to a circumstance or set of circumstances that caused the loss. Specifically, it measures the value of something before and after the causative act or omission creating the lost value in order to calculate compensatory damages. In legal damages theories, diminution in value is often calculated for compensatory special damages when a loss is monetarily quantifiable, and for restitution or disgorgement damages when the loss has unfairly enriched a wrongdoer.