When to Use Measures vs. Calc Columns

It's such a fundamental question. When you need to write a PowerPivot formula, which kind should you write - a calculated column or a measure (now renamed "calculated field" in 2013)?

Well, there is no perfect 100% answer to this question. But there are a handful of crucial differences and guidelines that make your choice clear 95% of the time. And the other 5% generally don't matter.

So let's get to those guidelines and differences, shall we?