Percentage to Letter Grade

How to Convert a Percentage to a Letter Grade

A percentage grade and a letter grade are two ways of reporting the same result, and most US schools translate between them with a fixed table of ranges. This converter uses the most common version of that table: enter any percentage from 0 to 100 (or a little above, for extra credit) and it returns the letter grade, the GPA points that letter earns on the standard 4.0 scale, and the full percentage band the score falls into.

How the Conversion Works

The conversion happens in two steps. First, the percentage is matched against a set of ranges: each letter grade owns a band of percentages, and your score belongs to exactly one band. Second, the letter grade is assigned a grade point value, which is what GPA calculations actually use. The percentage never converts directly to GPA points — it always passes through the letter grade first.

On the common scale, most bands are three or four points wide: an A- covers 90-92%, a B+ covers 87-89%, and so on down to D-, which covers 60-62%. Everything below 60% is an F. The one wide band at the top is A+ at 97-100%, and the one at the bottom is F, which absorbs the entire 0-59% range.

Percentage, Letter, and GPA Conversion Table

The 4.0, 4.3, and 4.33 columns differ in two ways. At A+: the standard 4.0 scale caps it at 4.0, while the other two award 4.3 or 4.33 points. And at plus/minus grades: the 4.0 and 4.3 scales use 0.3 steps (A- is 3.7), while the 4.33 scale uses thirds (A- is 3.67, B+ is 3.33). Whole letters — A, B, C, D, F — carry the same value on all three scales.

Worked Example: 88%

Say you finished a course with an 88%. Scanning the table, 88 falls in the 87-89% band, so the letter grade is a B+. A B+ is worth 3.3 grade pointson the 4.0 scale. That single chain — 88% → B+ → 3.3 — is the whole conversion. If the course is worth 3 credits, it contributes 3.3 × 3 = 9.9 quality points to your GPA.

Why Schools Differ

There is no national standard for grade bands, so treat this table as the common default rather than a universal rule. The two most frequent variations are:

• 10-point bands. Some schools use whole-letter ranges: 90-100 is an A, 80-89 is a B, and so on, often with no plus or minus modifiers at all. Under that policy, an 87% is a plain B, not a B+.
• Different minus/plus cutoffs. Even among schools that use modifiers, the lines move. One syllabus may set A- at 90-93.9%, another at 90-92%. A one-point shift in the cutoff can change your letter without changing your percentage.

Rounding policy is a third source of difference. Some instructors round 89.5% up to 90% before assigning letters; others truncate and count anything below 90.0% as a B+. Neither approach is wrong — but only the one printed in your syllabus applies to you.

Converting a Whole Transcript vs One Grade

A common mistake when estimating GPA from percentage grades is to average the percentages first and then convert the average. The correct order is the opposite: convert each course to a letter and grade points first, then average the points. The two orders can disagree, because the conversion table is not a smooth line — it moves in steps.

Here is a two-course example where the orders give different answers:

Converting each course first gives (3.7 + 3.0) ÷ 2 = 3.35. Averaging the percentages first gives (92 + 84) ÷ 2 = 88%, which converts to a B+ worth only 3.3. The 92% earned nearly the full value of its A- band, but that advantage disappears when it gets blended into a single percentage before converting. Over a full transcript the gap can grow larger, so always convert course by course — that is what the college GPA calculator does automatically.

Limitations

This converter uses the most common US grade bands, but your school's published ranges are the ones that count. It also cannot know your instructor's rounding policy, whether your school uses plus/minus modifiers, or whether a course applies a curve before letters are assigned. Use the result as a reliable default, and confirm boundary cases against your syllabus or registrar.