In the classic sense, a metric is a standard of measurement. The decimal system of weights and measures is a metric. A metric can also be a measure of performance toward a goal; it can be used to quantify, measure, and track value in an organization.

In environmental, health and safety (EHS), a metric is the measurable performance of an environmental or safety activity or program within an organization. Metrics can drive performance toward more efficient use of resources, improved compliance, profitability, and the general health and well-being of an organization and its workers. For example, an injury and illness tracking report can be used as a metric for employee productivity.

To be used in making business decisions, a metric must be consistent, comparable, credible, and relevant to the people using it. Business leaders focus on revenue, profit, market share, new products, and increasing capacity, productivity, or efficiency. By measuring the current situation compared to quantifiable goals, business leaders make data-driven decisions.

The best-run EHS operations employ a similar approach to decision making, one based on data and facts. Decisions related to the allocation of resources, technology purchases, training, employee performance, and outsourcing or internalizing EHS functions can all be based on data compiled through the use of appropriate metrics.