[leapis]

The way I've seen it calculated is this:

For regular classes, A: 4.0, B: 3.0, C: 2.0, D: 1.0 (with some variance depending on + or - grades offered). For Honors/AP classes, every grade is essentially bumped up 1.0 point.

So yes, a 3.74 is around an A- average, but that's an A- average in less rigorous classes, without competition from top students. That's more of a B-/C+ average in AP/Honors classes (obviously the calculation is far from perfect, though, because every school has it's quirks- at mine, you couldn't get above a ~4.5 overall). For reference, I graduated high school with a 3.6 with multiple Cs and hardly any As, simply by virtue of taking the maximum number of AP/Honors classes. The point being, a 3.74 is not a terrible GPA, but good students are generally over a 4.0 these days.

[Thorrez]

Most schools do that, but not all. My school (a private school in the US) didn't bump up anything.

[adjkant]

Colleges recalculate GPA's by high school to compare apples to apples. So even if your school doesn't, many colleges will use this weighting system.