Comprehensive Calculator Guide
The grade curve calculator helps teachers when a test turns out harder than intended, raising marks by one of two common methods: adding the gap between the top score and the full mark to everyone, or scaling so the top score becomes full marks. A 70 with a top score of 88 out of 100 becomes 82 by adding, or 79.55 by scaling. It compares the two and their effect on low scores.
Two methods, and when to curve
Adding the gap gives everyone the same points (here 12). Scaling multiplies every score by full ÷ top (100 ÷ 88), so higher scorers gain more in points. Either way the top student reaches full marks and the order stays the same.
Curve when the test itself was too hard, not for other reasons. Check the questions first — a flawed one is better dropped or re-marked — and announce the method and apply it to everyone.
How to Use
- Enter the student’s score and the top score in the class.
- Enter the full mark (100 by default) and choose a method.
- Press “Curve the score” to see the new score, points added and a comparison.
Formula Used
Add: score + (full − top) | Scale: score × full ÷ top
Practical Examples
- Example 1
- 70, top 88 of 100, adding: 82 (+12).
- Example 2
- Same, scaling: 79.55 (+9.55).
Important Tips
- Use the same method across all sections of a course.
Common Mistakes to Avoid
- Curving one student’s mark but not the class’s.
Frequently Asked Questions
- How do I curve grades?
- Add the gap between full marks and the top score to everyone, or scale by full ÷ top.
- Adding or scaling — which is better?
- Adding helps low scores more; scaling gives higher scores more.
- Does curving change the ranking?
- No, the order stays the same with both methods.