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-wrapper {
background-color: #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-title {
text-align: center;
color: #2c3e50;
margin-bottom: 25px;
font-size: 24px;
font-weight: 700;
}
.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; /* Ensures padding doesn't affect width */
}
.input-group input:focus {
border-color: #4dabf7;
outline: none;
box-shadow: 0 0 0 3px rgba(77, 171, 247, 0.25);
}
.btn-calculate {
width: 100%;
background-color: #228be6;
color: white;
border: none;
padding: 15px;
font-size: 18px;
font-weight: 600;
border-radius: 4px;
cursor: pointer;
transition: background-color 0.2s;
}
.btn-calculate:hover {
background-color: #1c7ed6;
}
.results-container {
margin-top: 25px;
background-color: #fff;
border: 1px solid #dee2e6;
border-radius: 4px;
padding: 20px;
display: none;
}
.result-row {
display: flex;
justify-content: space-between;
align-items: center;
padding: 10px 0;
border-bottom: 1px solid #f1f3f5;
}
.result-row:last-child {
border-bottom: none;
}
.result-label {
color: #868e96;
font-size: 14px;
font-weight: 500;
}
.result-value {
font-size: 20px;
font-weight: 700;
color: #212529;
}
.result-value.highlight {
color: #e03131;
font-size: 28px;
}
.result-value.good {
color: #2f9e44;
}
.article-content h2 {
color: #2c3e50;
margin-top: 30px;
border-bottom: 2px solid #e9ecef;
padding-bottom: 10px;
}
.article-content h3 {
color: #34495e;
margin-top: 20px;
}
.article-content p, .article-content li {
font-size: 16px;
color: #4a4a4a;
}
.formula-box {
background-color: #e7f5ff;
padding: 15px;
border-left: 4px solid #228be6;
font-family: monospace;
margin: 20px 0;
}
.example-box {
background-color: #f3f0ff;
padding: 15px;
border-radius: 4px;
margin: 20px 0;
}
.error-msg {
color: #fa5252;
font-size: 14px;
margin-top: 5px;
display: none;
}
function calculateChurn() {
// Clear errors
document.getElementById('startError').style.display = 'none';
document.getElementById('lostError').style.display = 'none';
document.getElementById('resultsContainer').style.display = 'none';
// Get Input Values
var startVal = document.getElementById('customersStart').value;
var lostVal = document.getElementById('customersLost').value;
// Parse Inputs
var customersStart = parseFloat(startVal);
var customersLost = parseFloat(lostVal);
var hasError = false;
// Validation Logic
if (isNaN(customersStart) || customersStart <= 0) {
document.getElementById('startError').style.display = 'block';
hasError = true;
}
if (isNaN(customersLost) || customersLost customersStart) {
alert("Customers lost cannot exceed customers at the start of the month.");
hasError = true;
}
if (hasError) {
return;
}
// Calculation Logic
// Formula: (Lost / Start) * 100
var churnRate = (customersLost / customersStart) * 100;
// Retention Rate: 100 – Churn
var retentionRate = 100 – churnRate;
// Customer Lifetime Value (in months): 1 / (Churn as decimal)
var lifetime = 0;
if (churnRate > 0) {
lifetime = 1 / (churnRate / 100);
} else {
lifetime = "Infinite"; // If churn is 0, lifetime is technically infinite
}
// Display Results
document.getElementById('churnRateResult').innerHTML = churnRate.toFixed(2) + '%';
document.getElementById('retentionRateResult').innerHTML = retentionRate.toFixed(2) + '%';
if (typeof lifetime === 'number') {
document.getElementById('lifetimeResult').innerHTML = lifetime.toFixed(1) + ' months';
} else {
document.getElementById('lifetimeResult').innerHTML = lifetime;
}
// Show Container
document.getElementById('resultsContainer').style.display = 'block';
}
How to Calculate Monthly Churn Rate
Understanding Monthly Churn Rate is critical for any subscription-based business, SaaS company, or membership organization. It represents the "leakage" in your bucket—the percentage of customers who cancel their subscriptions or stop buying from you within a specific month. High churn indicates product dissatisfaction or poor customer support, while low churn creates a solid foundation for compounding growth.
What is Monthly Churn?
Monthly churn is a metric that calculates the percentage of customers you lost during a month compared to the number of customers you had at the beginning of that month. It answers the simple question: "Of the people who were with us on the 1st, how many left by the 30th?"
The Churn Rate Formula
To calculate your monthly churn rate, you need two specific data points: total customers at the start of the month and the number of customers lost during that period. New customers acquired during the month are generally excluded from the denominator to keep the calculation clean.
Churn Rate (%) = (Customers Lost / Customers at Start of Month) × 100
Input Definitions:
- Customers at Start: The total count of active subscribers or paying customers on day 1 of the month.
- Customers Lost: The count of customers who cancelled or failed to renew during that month.
Example Calculation
Imagine a software company starts January with 500 active users. Throughout January, 25 of those users cancel their subscriptions.
- Customers at Start: 500
- Customers Lost: 25
- Calculation: (25 ÷ 500) = 0.05
- Percentage: 0.05 × 100 = 5% Monthly Churn
Related Metrics Explained
Our calculator provides two additional metrics derived from your churn rate:
1. Retention Rate
This is the inverse of churn. If your churn rate is 5%, your retention rate is 95%. It represents the percentage of customers you successfully kept.
2. Average Customer Lifetime
This is a predictive metric showing how long the average customer stays with you. It is calculated as 1 / Churn Rate. For example, with a 5% monthly churn rate, the average customer stays for 20 months (1 / 0.05).
What is a "Good" Churn Rate?
Benchmarks vary by industry, but generally:
- B2B Enterprise SaaS: Aim for less than 1% monthly churn.
- B2B SMB SaaS: 1% to 3% is acceptable; above 5% is dangerous.
- B2C Subscriptions (e.g., Netflix, Spotify): Often range between 2% and 6%.
Why Monthly Churn Matters for SEO and Growth
While often viewed as a financial metric, churn impacts your marketing efficiency. If your churn is high, you must spend significantly more on marketing (CAC) just to maintain the same revenue level. Lowering your churn rate is often the most effective way to increase profitability and Customer Lifetime Value (LTV).