Grade C- sits at 70 to 72 percent on the standard US grading scale and equals a 1.7 GPA on the 4.0 scale. It is one of the C-tier letters in the A-through-F sequence used at most US colleges and high schools, and counts as average academic standing on most transcripts. On a 4.3 scale, C- is worth 1.67 instead of 1.7.
What Grade C- Means on the Standard US Grading Scale
On the standard US grading scale used at most colleges and public high schools, grade C- covers 70 to 72 percent and converts to a 1.7 grade-point value when the transcript is summarized on the 4.0 GPA scale. C- is the lowest C tier and a common pass-fail threshold; many institutions set the floor for a Pass grade at C-.
Some US institutions adjust the percentage cutoffs by a few points: a school might publish an A floor of 90 instead of 93, or run a 7-point band for plus and minus tiers rather than the standard 3-point modifier shift. The 4.0 GPA value tied to grade C- is more consistent across schools than the percentage range, so it's worth verifying the specific cutoff with the registrar's published grading policy before relying on either reading.
How Grade C- Compares to Adjacent Letters
The plus and minus modifiers split each letter tier into three sub-bands worth 0.3 GPA points each. The table below shows how grade C- sits relative to the letter directly above and below on the standard scale, with percentage range and 4.0 GPA value for each.
| Letter | Percentage | 4.0 GPA | Standing |
|---|---|---|---|
| C | 73-76% | 2.0 | Average |
| C- | 70-72% | 1.7 | Average |
| D+ | 67-69% | 1.3 | Below average |
What GPA Is A C- on the 4.0 Scale?
A C- grade is worth 1.7 grade points on the standard 4.0 GPA scale used at most US colleges and high schools. On a 4.3 scale, C- is worth 1.67 instead of 1.7. On a credit-weighted transcript, every C- grade multiplies its course's credit hours by 1.7 to produce that course's contribution to the cumulative GPA total.
The arithmetic stays the same regardless of the course load: a C- in a 3-credit class contributes 5.1 quality points; the same C- in a 4-credit class contributes 6.8 quality points. Use the GPA calculator to model how a transcript with multiple C- grades and other letters resolves to a final cumulative GPA on the 4.0 scale.
Browse All Letter Grades on the US Scale
The US grading scale has 13 standard letters from A+ to F, plus two special variants (E historical, F- atypical). Use the chips below to jump to any letter's reference page, or see the full grading scale for all letters in one comparison table.
- Grade A+
- Grade A
- Grade A-
- Grade B+
- Grade B
- Grade B-
- Grade C+
- Grade C
- Grade C-
- Grade D+
- Grade D
- Grade D-
- Grade F
- Grade E
- Grade F-
Last verified: 2026-05-09. Sources: AACRAO transcript standards, NCES grade-distribution data, and the Mount Holyoke College historical record of the 1887 letter-grade adoption. Always verify the specific cutoff and GPA value with your school's registrar; institutional grading policies vary.