How the grading scale works
Most US schools grade on a 10-point scale: 90% and up is an A, 80–89% a B, 70–79% a C, 60–69% a D and anything below 60% an F. A D is usually the lowest passing grade.
Many high schools and colleges add plus and minus grades to tell the top and bottom of each range apart. They matter for GPA: a B+ is worth 3.3 points, a B− only 2.7. There is no universal plus/minus table, but the one above is the most common; some schools give an A+ 4.3 instead of 4.0.
Grading a test
Score = (questions − wrong) ÷ questions × 100
With 25 questions each one is worth 4%, so 3 wrong is 88% — a B. Rather than working it out for every paper, open the chart for your test length above, or use the Easy Grader, which also handles half points and custom scales.
Turning grades into GPA
Each letter maps to GPA points on the 4.0 scale (the GPA column above). To average your classes, use the GPA calculator; for what a GPA means, see the GPA chart.