Grading Scales Explained: Every Conversion Chart You Need
The same 85% can turn into a B, a B+, a 3.0, or a "Proficient" depending on which scale a school uses. This guide is the reference page for every conversion table you'll need — 10-point, 7-point, plus/minus, standards-based, pass/fail, and the systems used outside the US. If you need the underlying percentage formula instead, see how to calculate grades.
Standard 10-point scale
The most widely used scale in US K–12 schools. Every ten percentage points drops one letter grade.
| Letter | Percentage | GPA |
|---|---|---|
| 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 |
Example: a student who ends the semester at 87% in Algebra I earns a B on this scale, worth 3.0 GPA points.
7-point scale
Once standard in North Carolina and a handful of other districts, the 7-point scale pushes every boundary up, so the same 87% that was a B on the 10-point scale is still a B here — but an 84% drops to a C, whereas it stayed a B on the 10-point scale.
| Letter | Percentage | GPA |
|---|---|---|
| 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 |
Fewer districts use this scale today, but it still shows up on older transcripts, so it's worth checking before assuming a grade transfers directly.
Plus/minus scale
The plus/minus scale splits each letter into three bands and is the default at most US colleges and many high schools. It rewards a student at the top of a range (a 96% and an 89% both round to "B or better" territory only on flatter scales — here they land in different bands entirely).
| Letter | Percentage | GPA |
|---|---|---|
| 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 |
Worked example: a student finishes a college chemistry course at 91.4%. On the plus/minus table that's an A− (90–92%), worth 3.7 GPA points — not a flat 4.0, which is a common source of surprise for students used to a 10-point high-school scale.
Standards-based grading (1–4 scale)
Standards-based grading (SBG) reports proficiency on individual learning targets instead of averaging assignment scores into one percentage. Common in elementary schools and a growing number of middle schools.
| Score | Meaning | Rough letter equivalent |
|---|---|---|
| 4 | Exceeds standard | ≈ A / A+ |
| 3 | Meets standard (proficient) | ≈ B / A− |
| 2 | Approaching standard | ≈ C / D |
| 1 | Below standard | ≈ F |
The "rough equivalent" column is exactly that — rough. There's no standardized formula for converting a 3 on five different standards into a single letter grade; individual schools invent their own crosswalk, which is one reason SBG report cards look so different from district to district. For more on how schools combine these into report cards, see how schools calculate grades.
Pass/fail and credit/no credit
A simplified two-outcome scale used for electives, internships, and some college "audit" options. The underlying percentage still gets calculated the normal way — a course might require 70% to earn "Pass" — but only the pass/fail outcome appears on the transcript. Because there's no letter or GPA point attached, pass/fail courses typically don't affect GPA at all, which is why students sometimes choose it deliberately for a difficult elective.
International scales
Grading systems outside the US vary widely, and direct percentage comparisons are unreliable because grading philosophy differs, not just the number scale.
| System | Scale | Notes |
|---|---|---|
| UK (GCSE, new) | Grade 9 (highest) down to Grade 1 | 9–1 replaced A*–G in 2017 |
| UK (A-Level) | A*, A, B, C, D, E | A* ≈ 90%+ of A-band marks |
| Germany | 1 (sehr gut) to 6 (ungenügend) | 1 is the best mark, reversed from US |
| France | 0–20 point scale | 10/20 is typically a passing mark |
| IB Diploma | 1–7 per subject | Total out of 45 across six subjects plus core |
A German "2" (gut) is roughly a US B, but German teachers are traditionally more conservative about giving top marks, so a straight percentage-to-percentage comparison often understates a German student's actual standing.
Common mistakes
- Assuming all US schools use the same cutoffs. An 84% is a solid B on a 10-point scale and a C on a 7-point scale. Always check the syllabus, not general knowledge.
- Averaging letter grades directly. Averaging a B (3.0) and an A− (3.7) as "3.35" skips the actual percentage data and can misstate the real average — compute the percentage average first, then convert once. See how to calculate GPA.
- Treating SBG scores like percentages. A 3 out of 4 is not "75%" in the way a percentage grade is; it means "meets standard," and schools generally don't want families doing that math.
Limitations and edge cases
Conversion tables assume a grade sits cleanly within a school's declared scale, but real transcripts have exceptions: transfer credit from a school using a different scale, weighted GPA bumps for honors or AP courses, and rounding rules that shift a borderline score before it ever reaches the table (see grade rounding). When comparing grades across schools or countries, treat every table on this page as a starting approximation, not a legal conversion.
FAQ
Why did my 85% become a B in one class and a B+ in another?
The two classes are almost certainly using different scales — a 10-point scale where 80–89% is one flat B, versus a plus/minus scale where 83–86% is a B and 87–89% is a B+. Check the syllabus for the exact cutoffs.
Is a 4-point standards-based score the same as a GPA point?
No, even though both use a 1–4 range. A GPA point comes from converting an already-computed percentage or letter grade. A standards-based score of 4 reflects mastery of a specific learning target and isn't averaged the same way.
Which scale do most US colleges use?
Most four-year US colleges use a plus/minus letter scale converted to GPA points (A = 4.0 down through A−, B+, B, and so on). High schools vary more, with some still using a flat 10-point scale.
Once you know your percentage, convert it instantly with the letter grade calculator, or see the full grading scale chart for a printable reference.