Letter Grade Calculator

Example data table

This sample shows one common grading breakdown.

Grade scale thresholds and consistency

Letter grades are assigned by comparing your final percentage with fixed cutoffs. The plus/minus scale uses 97, 93, and 90 for A ranges, then steps down in three‑point bands for B and C. A standard scale uses 90, 80, 70, and 60. Keeping thresholds consistent across courses improves fairness, because identical performance produces identical outcomes. Many schools publish their cutoffs in syllabi, and aligning them with learning outcomes reduces disputes. If your institution uses different bands, edit the scale in code or treat results as an estimate only here.

Weighted components and normalization

In weighted mode, each component contributes Score × Weight. The calculator then divides by the sum of all weights, which automatically normalizes totals that do not equal 100. For example, weights of 20, 25, 30, and 25 sum to 100, but 10, 10, and 10 still work because the divisor becomes 30. This prevents accidental inflation when instructors choose compact weight sets.

Rounding choices near cut points

Rounding is applied before converting to a letter grade. This matters most within one percent of a cutoff. A score of 89.6 becomes 90 with “round up” and may move from B+ to A‑ on the plus/minus scale. “Round down” protects strict policies, while “nearest whole” matches many report cards. Use two decimals when you want the least distortion from raw scores.

Dropping lowest scores as a policy lever

Dropping the lowest components can reduce the impact of one missed quiz or an early low score. The calculator removes the lowest scores first and then recomputes the normalized weighted average using the remaining rows. This approach is transparent because dropped items are labeled in the breakdown. Schools often drop one low quiz when there are five or more short assessments.

Reporting, exports, and GPA interpretation

Results include the rounded percentage, letter grade, a GPA estimate on a 4.0 mapping, and a pass status based on your selected cutoff. Exports help document decisions: CSV is ideal for spreadsheets and audits, while PDF is best for sharing with students or guardians. When comparing terms, keep the same scale and rounding so GPA changes reflect learning, not settings.

FAQs

1) Can I use total weights that are not 100?

Yes. Weighted mode divides by the sum of weights, so any positive weights work. This keeps the final percentage accurate even when you use small, convenient weight numbers.

2) What happens if I enter scores above 100 or below 0?

Scores are clamped to the 0–100 range before calculation. This prevents out-of-range entries from creating unrealistic percentages and keeps grading decisions consistent.

3) Does dropping the lowest score drop by weight or by score?

It drops by lowest score first. After removal, the calculator recomputes the weighted average using the remaining rows and their weights, preserving the intended weighting plan.

4) Why does rounding change my letter grade?

Letter grades are based on thresholds. If your score is close to a cutoff, rounding can push it just above or below that boundary, changing the grade assignment.

5) Can I compute a grade from earned and possible points?

Yes. Choose the points mode and enter earned and possible totals. The calculator converts them to a percentage using (Earned ÷ Possible) × 100.

6) What do the CSV and PDF downloads include?

Both include the mode, percentage, letter grade, GPA estimate, pass status, and settings. If you used weighted components, the breakdown table is included as well.