Test percentages, letter grades, class averages, flat and square-root curves, and weighted categories — the everyday grading toolkit with every rule shown.
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FORMULA USEDTest Score Calculator
Grading arithmetic, made visible
Percentages, curves, and category weights are simple arithmetic that hides in awkward places — syllabus fine print, grading-policy debates, the question "what did the curve actually do to MY score". Each member shows its substituted formula, so the rule is never a mystery.
Two curving philosophies
A flat curve adds the same points to everyone: ranking is untouched, low and high scores gain equally. A square-root curve (new = 10√score) lifts low scores most: 36 becomes 60 while 96 only reaches 98. Neither is "fairer" — they answer different problems, and schools argue about them precisely because the choice changes who passes.
Worked example
Curve member, flat, with class average 71% and target 75%.
Bonus = 75 − 71 = 4 points for every student.
A 60% student moves to 64%; a 95% student to 99%.
Ranking is unchanged — that is the flat curve’s signature.
How to use it
Pick the grading task from the dropdown.
Enter your points, scores, or weights.
Read the result with its substituted formula.
Check against your syllabus — it always wins.
Frequently asked questions
How do I calculate my test percentage?
Divide points earned by points possible and multiply by 100. The member also gives the letter on the common 93/90/87 scale and the points you missed.
What does a square-root curve do?
It sets the curved score to 10×√(raw). It helps low scores most — 36→60 — while barely moving high ones. The multiplier is adjustable for gentler or harsher versions.
How do weighted categories work?
Each category average is multiplied by its weight (tests 40% = 0.40) and the products are added. The member refuses weights that do not sum to 100%.
Does a flat curve change my rank?
No — everyone moves by the same points, so order is preserved. That is the main argument for and against it.
What is a drop-lowest average?
The mean after removing your single lowest score — shown in the average member so you can see how much it helps.
Can this tell me what I need on the final?
That is a different calculation — the site has a dedicated Final Grade Calculator for exactly that question.