What's the most common high school grading scale?

This is possibly me overthinking things, but I was wondering, what's the most common grading scale used in high schools? I've always wondered if it varies across the country or if there's a standard universally used.

One of the most common grading scales in American high schools is the 4.0 scale. In this system, each letter grade corresponds to a number: A is 4.0, B is 3.0, C is 2.0, D is 1.0, and F is usually 0. Often, there are also +/- distinctions (such as A-, B+, and so on) that adjust the point value by a third of a point.

However, keep in mind that not every school utilizes the same scale. Some schools might consider an A- a 3.7 instead of a 3.67, for instance. Additionally, many schools use weighted scales for honors, AP, and IB classes, where a grade in one of these classes earns more points than the same grade in a regular course.

It's also worth noting that some schools go by a different system, such as percentage scales, a 100-point scale, or even a 10-point scale. But overall, the 4.0 scale is the most frequently used and is often the benchmark for college applications. However, colleges are quite familiar with variations in high school grading scales, and they will typically recalculate GPAs based on their scale anyway.