<p>Curves definitely vary from teacher to teacher, however it is pretty common for professors to grade based on the class at hand. Specifically thinking about the chemistry courses I have taken though, most curves are based on the class(es) that the professor is teaching themselves. It can usually be expected that an 100-85% is likely an A/A-, 85-70% is a B/B- and 70-65% is a C/C-. These will fluctuate depending on the difficulty of the course as well as the testing performance of the students.</p>
<p>The one time the curve did not fluctuate was when I took Physics and the teacher made it very clear that his curve was to be set, meaning you had to make the grades with no help from class averages. </p>
<p>The curves have done nothing but help me so far this year, I wouldn’t worry about them too much.</p>