proportionate

Proportionate is an adjective that denotes having or showing proper proportion; it describes a relationship in which one quantity corresponds in size, degree, or extent to another. In everyday usage, something is proportionate to a condition when it is appropriate or fair given that condition.

In mathematics and science, the related idea of proportionality describes a constant ratio between two quantities. A quantity that changes in proportion to another is described as proportional (for example, y is proportional to x). In common language, proportionate is often used interchangeably with proportional, but it more frequently emphasizes suitability or fairness rather than a strict mathematical ratio.

In law, ethics, and policy, the principle of proportionality requires that measures taken are appropriate and not excessive in light of the objective. This underpins judgments about punishment, military force, and administrative actions. A proportionate response is one that matches the severity of the incident, and a disproportionate response is considered excessive.

In design, art, and aesthetics, proportion refers to the size relationship among parts of a whole. Proportionate design aims for balance and harmony, ensuring components relate to one another in a way that is visually or functionally appropriate.

Common phrases include: proportionate to, which means "corresponding in size or degree to," and "proportionate representation" in civic contexts, although the more widely used term in political systems is proportional representation.