.ngr-calculator-wrapper {
max-width: 600px;
margin: 20px auto;
padding: 30px;
background-color: #f9f9f9;
border: 1px solid #e0e0e0;
border-radius: 8px;
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.ngr-calculator-wrapper h2 {
text-align: center;
color: #333;
margin-bottom: 25px;
border-bottom: 2px solid #d9534f;
padding-bottom: 10px;
}
.ngr-input-group {
margin-bottom: 20px;
}
.ngr-input-group label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: #555;
}
.ngr-input-group input {
width: 100%;
padding: 12px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box; /* Fix padding issue */
}
.ngr-input-group input:focus {
border-color: #d9534f;
outline: none;
}
.ngr-btn {
width: 100%;
padding: 15px;
background-color: #d9534f; /* Red to symbolize negative/decline */
color: white;
border: none;
border-radius: 4px;
font-size: 18px;
font-weight: bold;
cursor: pointer;
transition: background-color 0.3s;
}
.ngr-btn:hover {
background-color: #c9302c;
}
.ngr-result-box {
margin-top: 25px;
padding: 20px;
background-color: #fff;
border: 1px solid #ddd;
border-radius: 4px;
display: none;
}
.ngr-result-item {
display: flex;
justify-content: space-between;
margin-bottom: 10px;
padding-bottom: 10px;
border-bottom: 1px solid #eee;
}
.ngr-result-item:last-child {
border-bottom: none;
}
.ngr-result-label {
font-weight: 600;
color: #555;
}
.ngr-result-value {
font-weight: bold;
color: #333;
}
.ngr-negative {
color: #d9534f;
}
.ngr-positive {
color: #5cb85c;
}
.article-content {
max-width: 800px;
margin: 40px auto;
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
line-height: 1.6;
color: #333;
}
.article-content h2 {
color: #d9534f;
margin-top: 30px;
}
.article-content h3 {
color: #555;
margin-top: 25px;
}
.article-content ul {
margin-bottom: 20px;
}
.article-content li {
margin-bottom: 10px;
}
.formula-box {
background-color: #f4f4f4;
padding: 15px;
border-left: 4px solid #d9534f;
font-family: monospace;
margin: 20px 0;
}
function calculateNegativeGrowth() {
// Get input values using var
var startVal = document.getElementById('ngrStartValue').value;
var endVal = document.getElementById('ngrEndValue').value;
var periods = document.getElementById('ngrPeriods').value;
var resultBox = document.getElementById('ngrResult');
var periodRow = document.getElementById('periodRow');
// Validation
if (startVal === "" || endVal === "") {
alert("Please enter both Initial Value and Final Value.");
return;
}
// Parse numbers
var s = parseFloat(startVal);
var e = parseFloat(endVal);
var p = parseFloat(periods);
if (isNaN(s) || isNaN(e)) {
alert("Please enter valid numbers.");
return;
}
if (s === 0) {
alert("Initial Value cannot be zero (calculation results in infinity).");
return;
}
// Calculate Absolute Change
var absChange = e – s;
// Calculate Simple Percentage Change
// Formula: ((End – Start) / Start) * 100
var percentChange = ((e – s) / s) * 100;
// Calculate Compound Periodic Rate if periods exist and > 0
var periodicRate = 0;
var hasPeriods = false;
if (!isNaN(p) && p > 0) {
hasPeriods = true;
// CAGR / Compound Rate Formula: ( (End/Start)^(1/n) – 1 ) * 100
// Note: If end/start is negative, this results in NaN, but generally metric values are positive (e.g., revenue) even if growth is negative.
if (e 0) {
// Cannot calculate fractional power of negative base in this simple context
periodicRate = NaN;
} else {
periodicRate = (Math.pow((e / s), (1 / p)) – 1) * 100;
}
}
// Display Logic
resultBox.style.display = "block";
// Set Absolute Change Text
document.getElementById('resAbsChange').innerText = absChange.toFixed(2);
// Set Percent Change Text with styling
var pChangeText = document.getElementById('resPercentChange');
pChangeText.innerText = percentChange.toFixed(2) + "%";
if (percentChange 0) {
pChangeText.className = "ngr-result-value ngr-positive";
} else {
pChangeText.className = "ngr-result-value";
}
// Set Periodic Rate if applicable
if (hasPeriods) {
periodRow.style.display = "flex";
var pRateElem = document.getElementById('resPeriodRate');
if (isNaN(periodicRate)) {
pRateElem.innerText = "N/A (Base Negative)";
} else {
pRateElem.innerText = periodicRate.toFixed(2) + "%";
if (periodicRate < 0) pRateElem.className = "ngr-result-value ngr-negative";
else pRateElem.className = "ngr-result-value ngr-positive";
}
} else {
periodRow.style.display = "none";
}
// Set Status Text
var statusElem = document.getElementById('resStatus');
if (percentChange 0) {
statusElem.innerText = "Positive Growth (Increase)";
statusElem.style.color = "#5cb85c";
} else {
statusElem.innerText = "No Change";
statusElem.style.color = "#333";
}
}
How to Calculate Negative Growth Rate
In business, economics, and biology, monitoring trends is crucial for sustainability. While positive growth indicates expansion, negative growth (often referred to as contraction, decline, or decay) indicates a reduction in the measured metric over a specific period. Understanding how to calculate negative growth rate allows analysts to quantify losses, churn, or depopulation precisely.
The Negative Growth Rate Formula
The core concept of growth rate—whether positive or negative—is comparing a final value against an initial value relative to where you started.
Growth Rate (%) = ((Final Value – Initial Value) / Initial Value) × 100
When the Final Value is smaller than the Initial Value, the numerator (top number) becomes negative, resulting in a negative percentage. This negative sign represents the decline.
Example Calculation
Let's say a retail store had a monthly revenue of 50,000 in January (Initial Value) and this dropped to 45,000 in February (Final Value).
- Step 1: Find the difference.
45,000 – 50,000 = -5,000
- Step 2: Divide by the initial value.
-5,000 / 50,000 = -0.10
- Step 3: Convert to percentage.
-0.10 × 100 = -10%
In this scenario, the business experienced a negative growth rate of 10%.
Calculating Compound Negative Growth (Decay Rate)
If you are measuring a decline over multiple time periods (e.g., annual revenue decline over 5 years), using the simple formula above only gives you the total decline. To find the average rate of decline per period (Year-over-Year), you use the CAGR formula:
Periodic Rate (%) = [ (Final Value / Initial Value)^(1 / Number of Periods) – 1 ] × 100
This calculation helps smoothen out volatility to determine the steady rate at which a metric is shrinking.
Applications of Negative Growth Calculation
This calculator is useful for various scenarios, including:
- Customer Churn: calculating the percentage of subscribers lost over a month.
- Investment Loss: Determining the percentage decrease in a portfolio's value.
- GDP Contraction: Measuring economic recession indicators.
- Population Decline: Analyzing demographic shifts in shrinking cities or species populations.
Interpreting the Results
A "Negative Growth Rate" is mathematically synonymous with a positive "Decline Rate." For example, a growth rate of -15% is the same as saying revenue declined by 15%. When reporting these figures, context is key to ensure stakeholders understand that the metric is shrinking.