Year and policy note: Figures and policy examples labeled 2024 or 2025 reflect the source period stated in this guide. Verify current requirements with the institution or publisher before making a decision. There is no single U.S. high-school percentage-to-letter-to-GPA mapping.
A percentage, letter grade, grade point, and admission GPA are different fields
A score such as 90 does not have one portable letter or GPA value. The issuing policy determines:
- the percentage-to-letter cutoff;
- the letter-to-quality-point mapping;
- course credits and included terms;
- weighting eligibility and amount;
- rounding;
- pass/fail and incomplete treatment; and
- the effective school year.
A receiving college may then apply a separate admission calculation. That result does not replace the official high-school transcript GPA.
Build your grading-policy record
Copy these fields from the current official handbook:
| Field | What can vary |
|---|---|
| Effective year | A district can change cutoffs or grade symbols |
| Issuer | School, district, network, or another authority |
| Letter cutoffs | 90 may be A in one system and A− in another |
| Quality points | A+ may equal 4.0, exceed 4.0, or not be used |
| Weighting | Eligible courses, bonus amount, caps, and formula |
| Included work | Courses, terms, repeats, and transfer work |
| Credit | Course-credit value and attempted/earned treatment |
| Special grades | P/F, CR/NC, incomplete, withdrawal |
| Rounding | Precision and stage at which rounding occurs |
| Grade floors | Assignment, quarter, semester, or final-course scope |
Do not fill a missing field with a “standard” national chart.
Fairfax County example
Fairfax County Public Schools publishes this current division-wide percentage scale:
| Letter | Percentage |
|---|---|
| A | 93–100 |
| A− | 90–92 |
| B+ | 87–89 |
| B | 83–86 |
| B− | 80–82 |
| C+ | 77–79 |
| C | 73–76 |
| C− | 70–72 |
| D+ | 67–69 |
| D | 60–66 |
| F | 50–59 |
FCPS also publishes its quality points, credit inclusion, rounding method, and rules for grading floors and optional pass/fail. Those details belong together. The district changed part of its scale for 2025–26, showing why the effective year must be saved.
This is an FCPS example, not a national plus/minus table.
New York City example
New York City Public Schools says every school has a written grading policy reviewed and updated annually. Schools choose their scale from approved options such as 1–4, A–F, or 100-point, and may use another scale.
Therefore, “New York-style” does not identify one cutoff table. Families may request the school's own policy.
Weighting is also local
“Weighted GPA” does not automatically mean adding 0.5 for honors and 1.0 for AP. A policy may define eligible courses, bonus values, grade conditions, caps, or a different denominator.
A hypothetical weighted calculation is valid only when its assumptions are displayed. Adding a regular-course A can lower a weighted average under some formulas, but that arithmetic does not predict how a particular transcript is calculated.
Use the weighted GPA guide to understand the concept, then return to the official local policy for actual inputs.
Course credit and academic consequences are separate
A D, F, P, or incomplete can have different effects on:
- earned credit;
- graduation requirements;
- prerequisites;
- promotion;
- activity eligibility; and
- GPA.
Do not collapse these into one “passing grade” rule. A grade floor at the assignment or quarter stage is not automatically the final-course grade or GPA rule.
Receiving-college calculations
UC publishes a specific admissions GPA using defined A–G courses and terms, its own grade-point treatment, honors-point rules, and exclusions. Yale, by contrast, states that it does not unweight or reweight GPAs.
Those are named recipient practices. Neither is a national conversion from a high-school percentage to 4.0 GPA.
When an application requests the school's GPA, preserve the official value and scale. If it asks for a separate calculation, follow that recipient's exact instructions.
Use a calculator only after selecting the policy
A high-school GPA calculator can compute the scale and weights you enter. Before relying on the result:
- select or enter the correct school policy;
- verify the effective year;
- reproduce its credit and rounding rules;
- display assumptions beside the result; and
- label any hypothetical example as illustrative.
If the policy is unavailable, the correct output is “rule not verified,” not a default 90-to-A conversion.
Bottom line
The United States has no single high-school grading-scale chart. Document the issuing policy, effective year, cutoffs, quality points, weighting, credits, and rounding first. Named district examples illustrate variation; they do not create regional or national conversion rules.