What Grade Is 21 out of 30?
21 out of 30 is 70% — a C- on the standard US scale, a satisfactory score.
- Percentage70%
- Letter gradeC-
- Missed9 pts
- For an A (90%)27/30
Score breakdown for a 30-point test
| Score | Percent | Letter |
|---|---|---|
| 27/30 | 90% | A- |
| 24/30 | 80% | B- |
| 21/30 | 70% | C- |
| 21/30 | 70% | C- |
How this is calculated
Divide the points earned by the points possible and multiply by 100: 21 ÷ 30 × 100 = 70%. On the common 10-point-band scale that lands in the C- range — you'd have needed 27/30 to reach the A band.
Common questions
Can I still pass if I fail the final?
Often, yes — it depends on your current grade and the final's weight. With an 80 going in and a final worth 20%, even a 40 on the final leaves you at 72. Run your exact numbers in the calculator; 'failing the final means failing the class' is only true when the final is very heavily weighted or your cushion is thin.
What's the difference between weighted and unweighted averages?
An unweighted average treats every score equally: add them up, divide by the count. A weighted average multiplies each category by its share of the grade first — homework 20%, midterms 40%, final 40% — which is how most courses actually work. If your syllabus lists category percentages, you need the weighted version.