Exam Curve Calculator
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Z-score curve — preserve rank while shifting mean and spread.
Scores & distribution
Curved score
88
Z-score: 1
- Z-score
- 1
Related calculators
Curving with z-scores
A z-score curve preserves each student's relative standing. z = (your score − class mean) ÷ class standard deviation. Curved score = target mean + z × target standard deviation.
If the class averaged 72 with SD 10 and you want the curved exam centered at 80 with SD 8, a raw 82 (z = +1.0) becomes 80 + 1×8 = 88. This is a linear scale — it does not add flat points unless the target SD equals the original.
Example: raw 65, mean 72, SD 10 → z = −0.7. Target mean 80, SD 8 → curved ≈ 74.4. Verify your instructor's actual curve policy — some add fixed points instead.
Common questions
What if I don't know class standard deviation?
Ask the instructor or estimate from posted score ranges. Without SD, a flat bump curve cannot be modeled accurately here.
Is this the same as adding 5 points?
No. Adding points shifts everyone equally. Z-score scaling adjusts by how far you were from the mean.