Test Score Calculator
Convert points earned on a test into a percentage score and letter grade, with support for curve adjustments. Use it right after getting your graded exam back to understand where you stand.
About this calculator
Converting raw points to a percentage score is straightforward: Score (%) = ((pointsEarned + curvePoints) / totalPoints) × 100. This calculator adds a curve adjustment so you can account for bonus points or a teacher-applied curve before computing the final percentage. The result is rounded to two decimal places and capped at 100% using: Score = min(100, round(((pointsEarned + curvePoints) / totalPoints) × 100, 2)). Once the percentage is calculated, it is mapped to a letter grade using a standard or custom grading scale (e.g., A = 90–100%, B = 80–89%). This makes it easy to see not just your numerical score but also how it translates to your GPA.
How to use
You earned 67 points out of 80 on an exam, and your teacher added a 3-point curve. Score = min(100, round(((67 + 3) / 80) × 100, 2)) = min(100, round((70 / 80) × 100, 2)) = min(100, round(87.5, 2)) = 87.50%. On a standard grading scale, 87.50% is a B+. Without the curve, your score would have been (67/80) × 100 = 83.75%, a B — so the curve raised your letter grade by one step.
Frequently asked questions
How do I calculate my test score as a percentage?
Divide your points earned by the total possible points, then multiply by 100. For example, 45 out of 60 points is (45/60) × 100 = 75%. If your teacher applied a curve, add those bonus points to your earned points before dividing. This calculator handles all of that automatically and also maps the percentage to a letter grade so you don't have to look up a grading scale separately.
How does a grade curve affect my test score?
A curve adds extra points to your raw score before calculating the percentage, effectively shifting everyone's grade upward. For instance, a 5-point curve on a 100-point test raises an 80% to an 85%. Some instructors apply a multiplicative curve instead (multiplying all scores by a factor), but this calculator uses the common additive method. Always confirm with your instructor which type of curve they applied.
What is the difference between a percentage score and a letter grade?
A percentage score is a precise numerical measure of your performance, while a letter grade is a category that groups a range of percentages together. Most US institutions use a scale where 90–100% = A, 80–89% = B, 70–79% = C, 60–69% = D, and below 60% = F, though some schools use ± modifiers (A-, B+) for finer granularity. Letter grades matter for GPA calculations, while percentage scores give you more detail about how close you are to the next grade boundary.