KPI vs Metric: What's the Difference?

A metric is any quantifiable data point tracked from a marketing or business system - page views, click-through rate, follower count, email open rate - with no inherent judgment attached about whether the number is good, bad, or relevant to a specific goal.

A KPI (key performance indicator) is a metric that's been explicitly tied to a business objective and measured against a defined target, used specifically to judge whether progress toward that objective is happening.

The relationship is one of subset, not opposition: every KPI is a metric, but only a small number of metrics earn KPI status for a given goal. Follower count and follower growth rate are both metrics, for example, but if the actual objective is audience growth, only follower growth rate functions as the KPI - follower count alone doesn't say whether growth is happening or stalled. The same pattern holds across reporting generally: total revenue might be the KPI for an ecommerce campaign, while conversion rate, average order value, and retention are metrics that explain the movement behind that number rather than serving as the headline target themselves. A report that treats every metric as equally important is the most common version of this mistake - it produces a wall of numbers instead of a clear answer to whether the thing that was supposed to happen actually did, which is the reason reporting frameworks separate the two terms in the first place rather than treating "metric" and "KPI" as interchangeable.