Grade Curving Calculator
body {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
max-width: 800px;
margin: 0 auto;
padding: 20px;
}
.calculator-widget {
background: #f8f9fa;
border: 1px solid #e9ecef;
border-radius: 8px;
padding: 30px;
margin-bottom: 40px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.calc-h2 {
margin-top: 0;
color: #2c3e50;
text-align: center;
margin-bottom: 25px;
}
.input-group {
margin-bottom: 20px;
}
.input-group label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: #495057;
}
.input-group input {
width: 100%;
padding: 12px;
border: 1px solid #ced4da;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.input-group input:focus {
border-color: #4dabf7;
outline: none;
box-shadow: 0 0 0 3px rgba(77, 171, 247, 0.2);
}
.btn-calc {
width: 100%;
background-color: #339af0;
color: white;
border: none;
padding: 15px;
font-size: 18px;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
transition: background-color 0.2s;
}
.btn-calc:hover {
background-color: #228be6;
}
.result-box {
background: #fff;
border: 1px solid #dee2e6;
border-radius: 6px;
padding: 20px;
margin-top: 25px;
display: none;
}
.result-table {
width: 100%;
border-collapse: collapse;
margin-top: 15px;
}
.result-table th, .result-table td {
text-align: left;
padding: 12px;
border-bottom: 1px solid #e9ecef;
}
.result-table th {
background-color: #f1f3f5;
color: #495057;
}
.highlight-score {
font-weight: bold;
color: #2b8a3e;
font-size: 1.1em;
}
.method-desc {
font-size: 0.85em;
color: #868e96;
display: block;
margin-top: 4px;
}
.article-content {
margin-top: 50px;
}
.article-content h2 {
color: #2c3e50;
border-bottom: 2px solid #e9ecef;
padding-bottom: 10px;
margin-top: 30px;
}
.article-content p {
margin-bottom: 15px;
}
.article-content ul {
margin-bottom: 20px;
padding-left: 20px;
}
.article-content li {
margin-bottom: 10px;
}
.formula-box {
background: #f1f3f5;
padding: 15px;
border-left: 4px solid #339af0;
font-family: monospace;
margin: 15px 0;
}
function calculateCurve() {
var rawScore = parseFloat(document.getElementById('studentScore').value);
var maxPoints = parseFloat(document.getElementById('maxPoints').value);
var highest = parseFloat(document.getElementById('highestScore').value);
var flatBonus = parseFloat(document.getElementById('flatBonus').value);
if (isNaN(rawScore) || isNaN(maxPoints)) {
alert("Please enter at least your Raw Score and the Max Possible Points.");
return;
}
if (maxPoints maxPoints ? maxPoints.toFixed(2) : num.toFixed(2);
}
function getPerc(score) {
var p = (score / maxPoints) * 100;
return (p > 100 ? 100 : p).toFixed(1) + "%";
}
var html = "";
// Square Root Row
html += "
";
html += "| Square Root Curve√Score formula | ";
html += "" + fmt(rootScore) + " | ";
html += "+" + rootDiff.toFixed(2) + " | ";
html += "" + getPerc(rootScore) + " | ";
html += "
";
// Linear Scale Row
html += "
";
html += "| Linear ScaleTop score becomes 100% (Ratio) | ";
html += "" + fmt(linearScore) + " | ";
html += "+" + linearDiff.toFixed(2) + " | ";
html += "" + getPerc(linearScore) + " | ";
html += "
";
// Slide Row
html += "
";
html += "| Gravity / SlideAdds diff between top & max | ";
html += "" + fmt(slideScore) + " | ";
html += "+" + slideDiffVal.toFixed(2) + " | ";
html += "" + getPerc(slideScore) + " | ";
html += "
";
// Flat Bonus Row
if (flatBonus > 0) {
html += "
";
html += "| Flat BonusDirect points added | ";
html += "" + fmt(bonusScore) + " | ";
html += "+" + bonusDiff.toFixed(2) + " | ";
html += "" + getPerc(bonusScore) + " | ";
html += "
";
}
document.getElementById('resultBody').innerHTML = html;
document.getElementById('resultsArea').style.display = 'block';
}
Understanding the Grade Curving Calculator
Grade curving is a statistical method used by educators to adjust student scores based on the overall performance of the class. This Curving Calculator helps students and teachers estimate new grades using the most common mathematical curving methods.
Common Grade Curving Methods Explained
There is no single "correct" way to curve a test. Different institutions and departments prefer different formulas. Below are the methods calculated by this tool:
1. The Square Root Curve
This is one of the most popular methods for significantly boosting lower grades while having a minimal effect on higher grades. It is often used in difficult STEM subjects.
Formula: New Grade = √ (Raw Score) × 10
Note: If the exam is not out of 100, the formula is adjusted to: √(Raw ÷ Total) × Total. This method guarantees that a raw score of 100 stays 100, while a raw score of 36 boosts to 60.
2. Linear Scale (Ratio Method)
The linear scale is a proportional method. The teacher takes the highest score in the class and sets it equal to 100% (or the max possible points). Everyone else's score is multiplied by the same ratio.
Multiplier = Max Points ÷ Highest Class Score
New Grade = Raw Score × Multiplier
This method maintains the relative distance between students but shifts the entire distribution upwards proportionally.
3. The "Slide" or "Gravity" Curve
This is a simple flat addition method derived from the highest score. The teacher calculates the difference between the highest score and the maximum possible score (100%), and adds that number of points to everyone's grade.
Points Added = Max Points – Highest Class Score
New Grade = Raw Score + Points Added
This ensures the top student gets 100%, and every other student gets the exact same point increase.
Why Do Teachers Curve Grades?
Curving is often used when an exam is more difficult than anticipated or when the assessment questions were statistically invalid. It helps normalise the distribution of grades, ensuring that a specific percentage of students fall into the 'A', 'B', and 'C' ranges, rather than failing a large portion of the class due to a poorly designed test.
How to Use This Calculator
- Raw Score: Enter the grade you actually received.
- Max Possible Points: Enter the total points the exam was worth (usually 100).
- Highest Score in Class: Required for Linear and Slide methods. Ask your instructor or use the highest grade you know of.
- Flat Bonus: If your teacher simply said "everyone gets +5 points", enter that here to see the result.