Grading Scale Chart

How grading scales work in the US

A grading scale is the table that turns a percentage into a letter. There is no national scale, each school district, and often each teacher, publishes its own. Two patterns cover most US classrooms:

• The 10-point scale: 90% and up is an A, 80 to 89.9% a B, 70 to 79.9% a C, 60 to 69.9% a D, below 60% an F. It is the simplest and the most common.
• The 7-point scale: 93% for an A, 85% for a B, 77% for a C, 70% for a D, below 70% an F. The bands are narrower at the top, which makes an A harder to earn.

On top of the letters, many schools use plus and minus grades, which split each band into three and change the GPA points the grade is worth. The same 87% is a plain B on a 10-point scale, a B on a 7-point scale, and a B+ once plus/minus is switched on. Nothing about the student's work changed, only the table.

The calculator above applies the scale you pick, converts points to a percentage first if that is what you have, and then shows the letter, the GPA value and the distance to the next letter up.

Worked example: 87% on three different scales

Take a student who scored 87% on a test. Here is the same score read off three scales:

• 10-point scale: B. The B band runs 80 to 89.9%, so 87% sits 7 points above the bottom and 2.9 points below an A.
• 7-point scale: B. The B band runs 85 to 92.9%, so 87% is only 2 points above the floor and 6 points short of an A.
• 10-point with plus/minus: B+ (3.3 GPA points). The B+ band is 87 to 89.9%, so this is the bottom of the B+ range, 0.1 points lower and it would be a flat B worth 3.0.

The GPA swing between those readings is 0.3 points on one assignment. Across a semester of eight graded items, a student who keeps landing on the wrong side of a band edge can finish 0.2 or 0.3 GPA points lower than a classmate with the identical raw average.

Worked example: 43 out of 50 points

Points are just percentages in disguise. 43 out of 50 is 43 divided by 50 = 86%. On the 10-point scale that is a B, and it is 4 points clear of a C (which starts at 80%).

Now ask what it takes to move up. On the 10-point scale an A starts at 90%, which on this assignment is 45 points, so 2 more points out of 50, or one more multiple-choice question. On the 7-point scale an A starts at 93%, which is 46.5 points, so 3.5 more points. And if your school uses plus/minus, a B+ starts at 87% = 43.5 points, so a single half-point is the difference between a 3.0 and a 3.3 on the GPA.

That is the useful part of a grade chart: it converts a vague "I did okay" into a specific target. If the assignment is out of 200 points instead of 50, the same 3 percentage points becomes 6 points, the calculator scales it for you automatically.

Grade charts for the three common scales

These are the bands the calculator uses. Print it, stick it on the fridge, and check your school handbook against it, the 7-point column is where most surprises happen.

Notice the 70 to 72.9% row: it is a C on the 10-point scale, a D on the 7-point scale and a C- with plus/minus. Same work, three different transcripts.

From letter grades to GPA

GPA is an average of the points your letter grades are worth. On the standard unweighted 4.0 scale: A = 4.0, B = 3.0, C = 2.0, D = 1.0, F = 0.0. With plus and minus grades the values shift by thirds. A- 3.7, B+ 3.3, B- 2.7, C+ 2.3, C- 1.7, D+ 1.3, D- 0.7.

To average, multiply each grade's points by the credits the course is worth, add those up, and divide by the total credits. A student with four year-long courses who earns A, A, B and C has (4.0 + 4.0 + 3.0 + 2.0) divided by 4 = 3.25. Swap the C for a B and the GPA rises to 3.5, a 0.25 gain from one course.

Weighted scales go further: many schools add 1.0 for honors and AP courses, so an A in an AP class is worth 5.0 and a B is worth 4.0. That is why a student can graduate with a 4.2 GPA. When comparing students, always check whether the number is weighted or unweighted, because a 4.2 weighted can sit below a 3.9 unweighted in class rank.

The National Center for Education Statistics publishes the national picture on grades and transcripts, and the US Department of Education explains how schools report academic records.

How to move up one letter, and what it is worth

Going up one letter is almost always a small number of points. On the 10-point scale each band is 10 percentage points wide, so the distance from the top of one band to the bottom of the next is tiny, 89.9% to 90% is a tenth of a point, yet it is the difference between a B and an A on the transcript.

The practical targets: from a C to a B needs 10 percentage points, which on a 100-point test is 10 questions and on a 50-point quiz is 5. From a B to an A is another 10. With plus/minus grades the steps are smaller, 3 to 4 percentage points each, which is why students on those scales see more movement between assignments.

For a whole course, one test rarely does it. If a course grade is 80% classwork and 20% final exam, and you are sitting at 85%, then 85 x 0.8 + x x 0.2 = 90 needs x = 110%, impossible. You would have to raise the classwork instead, or ask about extra credit before the final. The same arithmetic where the final is worth 40% is much friendlier: 85 x 0.6 + x x 0.4 = 90 needs just 97.5%.

Admissions offices read the whole transcript rather than a single number. College Board's BigFuture walks through how colleges look at a high school record, including GPA, course rigour and grade trends.