ratio scale

A ratio scale is a way to measure things where the numbers have a meaningful order, equal intervals, and a true zero point. This means you can compare values in meaningful ways—such as saying one is twice as much as another. For example, weight is a ratio scale because 0 indicates no weight, and 10 pounds is twice as much as 5 pounds. Because of the true zero, ratios like “double” or “half” are valid, making ratio scales useful for precise measurements like weight, height, or income.