One of the more grave flaws of utilitarianism is that I've yet to hear anyone define utility in a quantifiable way. People often substitute 'happiness', but how

One of the more grave flaws of utilitarianism is that I've yet to hear anyone define utility in a quantifiable way. People often substitute 'happiness', but how does one measure happiness in a way that it can be calculated? Is it an absolute scale or is it relative to your own baseline? Happiness is also heavily subjective. People in the first world often feel like they're missing out if they don't feel like they have the latest and greatest iPhone, while someone in an extremely poor area would be happy to have running water. Is the utility of a new phone really the same as giving someone running water, or do we take into account that the need for a new phone is a somewhat self-inflicted societal standard? I like the concept of utilitarianism, but find that it's basis in statistics means that you can typically justify any position by tinkering with the parameters of how you measure utility.