How to Calculate a Grade Curve
Professor said they're curving the exam? Nice. But what does that actually mean for your score? Find out here. Flat curve, square root curve, custom scale — see your adjusted grade instantly.
Steps
Enter the original score
Type your raw exam score and the total points possible. Got a 62 out of 100? Enter both numbers. The calculator needs your raw data before it can do anything with a curve.
Choose the curving method
Pick whatever curve type your professor mentioned. Flat curve? Same number of points added to everyone. Square root curve? Takes the square root of your percentage and multiplies by 10 — helps lower scores way more than higher ones. Custom scale? You set the mapping yourself.
Enter curve parameters
Flat curve? Enter the points added (like +8). Square root? The calculator runs the formula on its own. Custom scale? Enter the new cutoffs — maybe 85+ counts as an A now instead of 90+.
Compare original vs. curved grade
You see your original percentage and letter grade right next to the curved versions. That 62% might jump to 79% under a square root curve. D to C+. Big difference.
How Different Curves Affect Your Score
Not all curves work the same way. A flat +10 treats everyone identically. Your 62 becomes 72. The person who got 88 becomes 98. The gap stays exactly the same. A square root curve? That compresses the gap. Your 62 becomes roughly 79 (sqrt of 62 times 10). The 88 becomes roughly 94. So the lower you scored, the bigger your boost. Then there's linear scaling — it maps the highest score to 100 and adjusts everyone proportionally. If the top score was 92, your 62 becomes about 67. Less generous if you're near the bottom. The point: knowing which method your professor uses lets you estimate your adjusted grade before anything gets posted officially.
Frequently Asked Questions
Flat curve, hands down. Adding X points to everyone is the simplest approach. Professor sees the class average is low, decides it should've been 10 points higher, and bumps everyone by 10. Square root curve is second most popular — it gives a bigger boost to students who scored lower without helping the top scorers as much.
With a flat curve? Totally. If you scored 95 and the professor adds 10, that's 105. Most professors cap it at 100. Some don't. The calculator shows the raw number — ask your professor about any cap.