Grade Curve Calculator
Apply a linear curve to a test score.
The score the class top is lifted to (usually 100).
Results update as you type.
How it works
A grade curve calculator applies one of the most common curving methods a teacher can use: a flat linear shift that raises the top score in the class up to a target maximum and adds that same boost to every other student's score. You enter your own raw score, the highest score anyone in the class achieved, and the maximum you want that top score lifted to — usually 100 — and the tool works out the bonus and applies it to you. This method is popular because it is transparent and fair in a specific way: everyone receives the identical number of points, so the ranking of the class never changes, but a test that turned out harder than intended is corrected so the best performance anchors the top of the scale. If the highest score was an 88 and the target is 100, every student gains 12 points, turning your 70 into an 82. The calculator makes it trivial to see where a curve leaves you before official grades are posted, and to understand how much a curve is actually worth given the class's top mark. Students use it to gauge the effect of a rumoured curve, and teachers use it to preview how a flat adjustment would reshape a set of results. Because it is a straight addition, the curve preserves the gaps between students exactly; it lifts the whole distribution without stretching or compressing it, which is why it is often the least controversial way to soften a difficult exam.
curved = your score + (target maximum − highest class score)
The curve finds the gap between the target maximum and the highest score anyone actually earned, then adds that fixed gap to every student's score. Because the same number of points is added across the board, the difference between any two students stays identical and the class ranking is untouched — the entire distribution simply slides upward until the top score reaches the target. Your curved score is therefore your raw score plus that constant bonus, which is why a larger gap between the class high and the target produces a bigger lift for everyone.
Source:Linear (flat-shift) curving method
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter your score and highest score in class.
- 2
Adjust the options
Adjust target maximum if they apply — sensible defaults are already set.
- 3
Read your result
Curved score updates instantly as you type — no button to press.
Frequently asked questions
How does this curving method work?
It is a flat linear shift. The calculator finds how far the highest score in the class falls short of the target maximum, then adds that same number of points to every student, including you. If the top score was 88 and the target is 100, everyone gains 12 points. Because the bonus is identical for all, the order of the class is preserved and only the overall level rises, anchoring the best performance at the top of the scale.
Does everyone get the same number of points?
Yes, that is the defining feature of this method. Every student receives an equal boost equal to the gap between the class's highest score and the target maximum. This keeps the relative standing of everyone unchanged — the gaps between scores stay exactly the same — while lifting the whole class so the top mark reaches the target. It is often seen as the fairest simple curve precisely because it advantages no one over anyone else.
Are there other ways to curve grades?
Yes, several. Some instructors scale scores as a percentage of the top mark rather than adding a flat amount, which stretches the distribution. Others fit grades to a bell curve, assigning fixed proportions of each letter grade, or add a flat bonus unrelated to the class high, or drop the hardest question. Each method reshapes results differently. This calculator models the flat linear shift to the top score, so confirm which method your instructor actually intends to use.
Can a curved score go above 100?
With this method the top student lands exactly at the target maximum, usually 100, and everyone else finishes below them, so scores should not exceed the target. However, if you enter a target higher than 100, or a student somehow scored above the value you listed as the class high, the arithmetic could produce a figure over 100. Check your inputs, and remember many schools cap final scores at 100 regardless of the raw curved result.
Why would a teacher curve a test at all?
Curving usually corrects a test that proved harder than intended, where even well-prepared students scored lower than the material warranted. Rather than penalise the whole class for an overly difficult exam, an instructor lifts the scores so the strongest performance anchors the top. Curves can also standardise results across sections or align a class to a target average. A flat shift like this one is common because it is simple, transparent and does not change who ranks ahead of whom.