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Free Online Grade Tool

Grade Curve Calculator

Use this grade curve calculator to curve test scores online. Enter your raw score, total points, and curve method to instantly calculate the curved percentage, letter grade, added points, and class results.

Grade Curve Calculator

This calculator supports the most common test curve methods used by teachers, professors, tutors, and students. You can calculate one student’s curved grade or curve an entire class using the batch calculator below.

Important: The result is an estimate unless your teacher has officially announced the exact curve method.


Enter the points earned on the test.


Enter the maximum possible score.




Example: 72/100 plus 5 points becomes 77/100.



Example: 72% plus 8 percentage points becomes 80%.





Letter Grade Scale

Customize the grading scale according to your class, school, college, or teacher.









Class Grade Curve Calculator

Paste multiple scores to curve an entire class. Enter one score per line, separate scores by commas, or use score fractions such as 43/50.



Plain scores use the total possible points entered in the main calculator.

Paste class scores to calculate curved results.

What Is a Grade Curve Calculator?

A grade curve calculator is a tool that adjusts raw test scores using a selected grading curve method. Students use it to estimate their final curved grade, while teachers can use it to understand how different curves affect class results.

Curved Grade = Raw Grade + Curve Adjustment

Common Grade Curve Methods

Curve MethodHow It WorksExample
Add fixed pointsAdds the same number of test points to every score.72/100 + 5 points = 77%
Add percentage pointsAdds the same percentage-point increase to every grade.72% + 8 = 80%
Highest score to 100%Raises the highest class score to 100% and adds the same percentage-point difference to everyone.If highest score is 92%, add 8 percentage points.
Target average curveRaises or lowers grades so the class average reaches a selected target.If current average is 68% and target is 75%, add 7 points.
Square-root curveUses a nonlinear formula that raises lower scores more strongly.64% becomes 80%.

Square Root Grade Curve Formula

Curved % = √(Raw % ÷ 100) × 100

The square-root curve is usually more generous for lower scores. For example, 49% becomes 70%, 64% becomes 80%, and 81% becomes 90%.

How to Use This Grade Curve Calculator

  1. Enter the raw score earned.
  2. Enter the total possible points.
  3. Select the curve method.
  4. Enter the required curve value, such as points to add or highest score.
  5. Click Calculate Curved Grade.

When Should a Test Be Curved?

A test may be curved when the exam was unusually hard, the class average is much lower than expected, or the teacher wants grades to reflect relative class performance. However, the official curve always depends on the teacher’s grading policy.

Grade Curve Calculator FAQs

How do I calculate a curved grade?

Convert the raw score to a percentage, then apply the chosen curve method. For example, if the raw grade is 72% and the curve adds 8 percentage points, the curved grade is 80%.

What is the easiest grade curve method?

The easiest method is adding the same number of percentage points to every score. For example, a 75% grade becomes 85% if the curve adds 10 percentage points.

How does curving the highest score to 100 work?

This method calculates the difference between the highest class score and 100%. If the highest score is 92%, the calculator adds 8 percentage points to every score.

Can a curved grade be over 100%?

Some teachers cap curved grades at 100%, while others allow scores above 100% as extra credit. This calculator includes both options.

What is a square-root grade curve?

A square-root curve uses the formula √(raw percentage ÷ 100) × 100. It raises lower grades more strongly than higher grades.

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Engr. Muhammad Yar Saqib author profile photo

Engr. Muhammad Yar Saqib

Engr. Muhammad Yar Saqib is an electrical engineer educated at the University of Bradford, United Kingdom, a writer and poet, and an Assistant Education Officer in the School Education Department, Punjab, serving since July 2017. He writes practical guides on statistics, SPSS, data analysis, mathematics and educational technology, with an emphasis on transparent methods, reproducible calculations and ethical learning support.