What Grade Is 80 out of 100?
80 out of 100 is 80% — a B- on the standard US scale, a good score.
- Percentage80%
- Letter gradeB-
- Missed20 pts
- For an A (90%)90/100
Score breakdown for a 100-point test
| Score | Percent | Letter |
|---|---|---|
| 90/100 | 90% | A- |
| 80/100 | 80% | B- |
| 70/100 | 70% | C- |
| 80/100 | 80% | B- |
How this is calculated
Divide the points earned by the points possible and multiply by 100: 80 ÷ 100 × 100 = 80%. On the common 10-point-band scale that lands in the B- range — you'd have needed 90/100 to reach the A band.
Common questions
How are letter grades calculated from percentages?
Most US schools map percentages to letters in 10-point bands: 90–100 is an A range, 80–89 a B range, 70–79 a C range, 60–69 a D range, and below 60 an F. Plus/minus splits each band roughly in thirds (e.g. 90–92 = A-, 93–96 = A, 97+ = A+). Individual schools and professors can and do vary the cutoffs.
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.