Grading Scale Converter
Turning a percentage score into a letter grade and a grade-point value is simple once you fix the cutoffs, but those cutoffs differ between schools: some award an A at 90 percent and others at 93. This converter takes your percentage and your own A, B, C, and D thresholds, then returns the matching letter grade and its 4.0-scale point. Because there is no single national grading scale, every threshold is a user-editable input, so the result reflects your institution's published policy rather than a hardcoded assumption.
Conversion rule
score >= A cutoff: A, 4.0
score >= B cutoff: B, 3.0
score >= C cutoff: C, 2.0
score >= D cutoff: D, 1.0
otherwise: F, 0.0
The thresholds are compared from highest to lowest. Points to next letter is the percentage gap up to the next higher cutoff.
Notes
- Confirm your school's exact cutoffs; a 93 versus 90 A boundary changes the letter.
- The 4.0-scale points (4, 3, 2, 1, 0) are the most common unmodified mapping.
- Plus and minus modifiers vary by institution and are not applied here.
- D is treated as the lowest passing grade in many scales, but some courses require a C.
- Use this per-assignment or per-course; a full GPA averages points across courses.
Grading scale: frequently asked questions
How does a percentage map to a letter grade?
A common U.S. scale uses A for 90 percent and above, B for 80 to 89, C for 70 to 79, D for 60 to 69, and F below 60. Cutoffs vary by institution, so this calculator lets you set the A, B, C, and D thresholds yourself rather than assuming one fixed scale.
What GPA point does each letter earn?
On the standard 4.0 scale, A is 4.0, B is 3.0, C is 2.0, D is 1.0, and F is 0.0. Many schools add plus and minus modifiers (for example A- is 3.7, B+ is 3.3), but the unmodified four-point mapping is the most widely shared baseline this tool uses.
Why are the cutoffs editable?
Grading scales differ between schools, departments, and even individual courses. Some use a 93 cutoff for an A, others 90. Because there is no single national standard, the calculator keeps the thresholds as user-editable inputs so you can match your syllabus exactly.
Does this handle plus and minus grades?
This converter uses the core letters A through F and their whole-number GPA points. Plus and minus refinements vary widely between institutions, so for those you should consult your registrar's published scale and adjust the GPA point accordingly.
Can I convert a GPA point back to a percentage?
Not precisely. A letter grade spans a range of percentages, so a single GPA point does not map to one exact percentage. The conversion runs reliably from a percentage to a letter and point, which is the direction grade reports require.
Official sources
- National Center for Education Statistics: NCES (grading and GPA reporting).
- U.S. Department of Education: official site.
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. Cutoffs are user-editable to match institutional policy. See our methodology.