How do letter grades correspond to GPA on a 4.0 scale?

Okay, so I get that AP classes can boost my GPA because they're weighted, but how exactly do letter grades translate to GPA points on the 4.0 scale? Does it differ a lot between high schools?

I'm happy to explain the basics of the GPA scale to you! On a standard unweighted 4.0 GPA scale, an A is typically equivalent to 4.0, a B is equivalent to 3.0, a C is equivalent to 2.0, a D is typically 1.0, and an F is 0.0. For AP or honors classes, many schools use a weighted GPA scale to reflect the increased difficulty. On a weighted scale, an A might count as 5.0, a B as 4.0, and so forth.

The specifics can vary between schools as some may use a plus/minus system (e.g., an A- could be a 3.7), and some do not. It's not standardized across the board, so your high school's policy on GPAs is the one that colleges will consider when they look at your transcripts. Most high schools will have a guide or scale that shows their particular conversion. Check with your counselor or look at your school's grading policy to understand precisely how your letter grades will convert to GPA points.