Letter Grade Scale and Percentage Chart
Last updated: October 13, 2026
There is no single letter grade scale that every school uses. The scales below are common in the United States. Your syllabus or school handbook has the one that applies to you.
Basic scale
| Letter grade | Percentage | Grade points (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 |
Scale with plus and minus grades
| Letter grade | Percentage | Grade points (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 |
Some schools count an A+ as 4.3 instead of 4.0, and some do not give an A+ at all.
How to calculate a letter grade
- Work out your percentage: points earned ÷ points possible × 100. See how to calculate a grade percentage.
- Find the range that contains it on your school’s scale.
- Read the letter, and the grade points if you are working out a GPA.
Example: 43 out of 50 is 86%. On the plus and minus scale that is a B, worth 3.0 grade points. On the basic scale it is also a B.
Borderline grades and rounding
A grade just below a cutoff, like 89.6%, may or may not round up. Some teachers round to the nearest whole number, some use the exact value and some apply a different cutoff for each letter. The calculator shows the grade to two decimals, so you can see how close you are. If you are within half a point, it is worth asking.
Why scales differ
Some schools start an A at 93% or 94%, and some set a different cutoff for passing. Colleges and individual teachers can also set their own. Many professional and graduate programs use 70% as the minimum passing grade. If your cutoffs are different, use yours.
Match the calculator to your school
In Grade Calculator you can adjust the letter grade cutoffs so the letter shown next to your class grade matches your school. To turn letter grades into a GPA, read how to calculate your GPA.
Frequently asked questions
What percentage is an A?
On the most common scale an A is 90% to 100%. Some schools start an A at 93% or 94%, and a plus and minus scale splits it into A+, A and A−.
What percentage is a B?
A B is usually 80% to 89%. With plus and minus grades that splits into B+ (87–89%), B (83–86%) and B− (80–82%).
What is the lowest passing grade?
In many schools a D at 60% is the lowest passing grade, but some courses and programs require a C or 70% to count for credit. Check your school’s policy.
How do I calculate letter grades for a whole class?
Work out the class percentage first, then match it to the scale. Letters are not averaged directly. They come from the percentage.
Calculate it automatically
Paste your gradebook into Grade Calculator and the table fills in on its own. Change any score, or add an upcoming assignment, to see your class grade update.