Utility....happiness "measured"

Utility is defined as the satisfaction gained from consuming a good or service. In fact, economists sometimes use "utils" to quantify utility to show differences between g/s and different consumption rates. Utility does exhibit diminishing returns (the law of diminishing marginal utility). This means that although total utility goes up and up at ever-increasing rates in the beginning, eventually diminishing returns occur and the increase of consuming the next unit is not as high as the one before. Eventually, the total utility can begin to decrease. Imagine this using glasses as cola as an example. After your 13th glass, you may have a serious problem (and "negative utility!").