Grading scale: letter grades, percentages and GPA
Most US schools use a 10-point grading scale: A is 90–100%, B 80–89%, C 70–79%, D 60–69% and F below 60%. Many add plus and minus grades, and some use a stricter 7-point scale. Below are all three, with GPA points, and how to get from a test score to a letter grade.
Updated October 2026
These are common conventions, not national rules. Your school or district sets the official scale, rounding and GPA points. To grade a test right now, use the free easy grader.
The 10-point grading scale
The most common US scale: A from 90, B from 80, C from 70, D from 60.
| Letter | Percentage | GPA (4.0 scale) |
|---|---|---|
| A | 90–100% | 4.0 |
| B | 80–89% | 3.0 |
| C | 70–79% | 2.0 |
| D | 60–69% | 1.0 |
| F | Below 60% | 0.0 |
The grading scale with plus and minus grades
The same 10-point scale, split into plus and minus grades. An A+ is usually worth the same 4.0 as an A; a few schools give it 4.3.
| Letter | Percentage | GPA (4.0 scale) |
|---|---|---|
| A+ | 97–100% | 4.0 |
| A | 93–96% | 4.0 |
| A− | 90–92% | 3.7 |
| B+ | 87–89% | 3.3 |
| B | 83–86% | 3.0 |
| B− | 80–82% | 2.7 |
| C+ | 77–79% | 2.3 |
| C | 73–76% | 2.0 |
| C− | 70–72% | 1.7 |
| D+ | 67–69% | 1.3 |
| D | 63–66% | 1.0 |
| D− | 60–62% | 0.7 |
| F | Below 60% | 0.0 |
The 7-point grading scale
A stricter scale some districts use: A from 93, B from 85, C from 77, D from 70. It makes each letter harder to reach, and F starts below 70.
| Letter | Percentage | GPA (4.0 scale) |
|---|---|---|
| A | 93–100% | 4.0 |
| B | 85–92% | 3.0 |
| C | 77–84% | 2.0 |
| D | 70–76% | 1.0 |
| F | Below 70% | 0.0 |
Turning a test score into a percentage
Divide what the student earned by what was possible, and multiply by 100. With questions worth one point each, that is correct answers ÷ questions: 17 of 20 is 85%. With points, use points: 34 of 40 points is also 85%. The easy grader does it for every possible number wrong at once, with half points if you need them.
Rounding
Many gradebooks round to the nearest whole number, so 89.5% becomes 90% and an A. Others don't round, or round only final grades. There is no single rule; whatever yours is, say it in the syllabus so students know where the lines are.
Weighted grades
Many teachers weight categories differently, so a test counts more than homework. Multiply each category's average by its weight and add them up.
| Category | Weight | Student's average | Counts for |
|---|---|---|---|
| Tests | 50% | 82% | 41 |
| Quizzes | 30% | 90% | 27 |
| Homework | 20% | 100% | 20 |
| Final grade | 88% (B+) |
The same student would have 90.7% if the three categories counted equally, which is why weights belong in the syllabus too.
GPA
Grade point average turns letters into points on a 4.0 scale (A 4.0, B 3.0, C 2.0, D 1.0, F 0) and averages them across courses, usually weighted by credits. Many high schools also report a weighted GPA, adding extra points for honors, AP or IB courses, so it can go above 4.0. How much extra varies by school.
Standards-based grading
Some schools replace percentages with a 1–4 scale for each standard, for example 4 exceeds, 3 meets, 2 approaching and 1 beginning. Instead of averaging everything into one number, it reports where a student stands on each skill. It pairs naturally with formative assessment: the goal is to show what a student can do now, not to average in their early attempts.
Grades are the end of the story, not the useful part
Mentora grades every answer against your rubric, written answers included, and tells you what the class understood and what to reteach, so the next grade can be better than this one.
Frequently asked questions
What is the standard grading scale?
In most US schools: A is 90–100%, B 80–89%, C 70–79%, D 60–69% and F below 60%. Many schools add plus and minus grades, and some use a stricter 7-point scale. Your school or district sets the official one.
What percentage is a B?
On the 10-point scale, 80–89%. With plus and minus grades, a B is usually 83–86%, a B+ 87–89% and a B− 80–82%. On a 7-point scale, a B is 85–92%.
What is a passing grade?
Often a D (60%) passes a course, but many schools, programs and individual requirements ask for a C (70%) or better. Check your school's policy.
Is 89.5% an A or a B?
It depends on the rounding policy. Where scores are rounded to the nearest whole number, 89.5% becomes 90%, an A on the 10-point scale. Where they aren't, it stays a B. Schools and teachers decide this, so it's worth stating in the syllabus.
What GPA is a B+?
Usually 3.3 on a 4.0 scale. An A is 4.0, an A− 3.7, a B 3.0 and a B− 2.7. Some schools use slightly different points, and honors or AP courses are often weighted higher.
Keep going
- Free easy grader: percentages and letter grades for every possible number wrong.
- Formative vs. summative: when a grade measures learning, and when a check should change it.