Linear Grade Curve Calculator

Curve scores with a flat bump to top 100 and letter.

What it does

Linear curves lift every paper by the gap to the top. If the best scores 85, adding 15 makes that paper 100 and a 78 becomes 93. Order stays, spacing stays, only the zero point moves.

The tool above takes raw score and class top and returns curved score, bump, and letter. The defaults 78 with top 85 match the worked example, so the page opens showing 93% (A).

Bump is 100 minus top. Curved adds bump to raw and caps at 100. Letters follow 90/80/70/60 cutoffs. Here bump 15 turns 78 to 93, an A. A 65 with top 92 bumps 8 to 73, a C.

Use flat curves for hard tests with low tops. For spread changes use scale or square root curves instead. Announce method before the test to keep trust.

This page shows the formula, one full hand checked example at 78 with top 85, a reference table, and practice checks that run through the tool.

How to use

1. Type your raw score 0 to 100.
2. Type class top score, the max that becomes 100.
3. Check raw sits at or below top.
4. Read Curved score as the main result.
5. Read Bump as points added.
6. Read Letter on 90/80/70/60 cuts.

Formula

raw

Your score before curve.

top

Class max that maps to 100.

bump

Points added to every paper.

Caps at 100. Order preserved. For other methods like root curves use other tools.

Worked example

Reference table

Limits

• Flat shift only. Spread never changes.
• Raw at or below top required.
• Caps at 100.
• Letters use fixed 90/80/70/60 here.

Common mistakes

• Curving above top by entering raw over max.
• Adding bump twice.
• Expecting rank changes. Order never flips here.
• Using flat for wide spreads that need scaling.
• Hiding method until after scores post.

Try it yourself

Quick checks. Answers sit tucked under each question.

Questions

Sources

• College Board
• Khan Academy Math

Related calculators