Grade Calculator

Two calculators for students: turn a raw score into a percentage, and work out what you need on the final.

Score as a percentage

Score84%
Letter grade (common US scale)
B
Points missed
8

Working

  1. 42 ÷ 50 × 100 = 84%

Grading scales differ between schools and countries. Check your course’s own scale for the official letter grade.

Score needed on the final exam

Score needed on the final100%

Working

  1. Needed = (target − current × (1 − weight)) ÷ weight = (88 − 84 × 0.75) ÷ 0.25 = 100%

Formulas

score % = earned ÷ possible × 100

needed = (target − current × (1 − w)) ÷ w

Here w is the final exam’s weight as a decimal (25% → 0.25), and “current” is your grade on everything else.

Worked example

Current 84%, target 88%, final worth 25%

  1. Everything else counts for 75%: 84 × 0.75 = 63
  2. Points still needed: 88 − 63 = 25
  3. Divide by the final’s weight: 25 ÷ 0.25 = 100

You would need 100% on the final.

Common US letter scale

PercentageLetter
97–100A+
93–96A
90–92A−
87–89B+
83–86B
80–82B−
77–79C+
73–76C
70–72C−
67–69D+
63–66D
60–62D−
Below 60F