Churn Rate Calculator
Quickly compute churn rate with accurate formulas. See amortization schedules, growth projections, and side-by-side comparisons.
Calculator
Adjust values & calculate12-Month Customer Projection
Revenue Impact
Formula
Churn rate is the percentage of customers lost during a period. Retention rate is its complement. Annual churn compounds monthly: Annual = 1 - (1 - Monthly Rate)^12. Average customer lifetime in months = 1 / Monthly Churn Rate.
Last reviewed: December 2025
Worked Examples
Example 1: SaaS Monthly Churn
Example 2: Low-Churn Enterprise Product
Background & Theory
The Churn Rate Calculator applies the following established principles and formulas. Break-even analysis identifies the sales volume at which total revenue equals total costs, producing neither profit nor loss. The formula divides total fixed costs by the contribution margin per unit, where contribution margin equals selling price minus variable cost per unit. If a software product has $50,000 in monthly fixed costs and each licence generates $20 above its variable cost, break-even requires 2,500 unit sales per month. Above that threshold, each additional unit contributes directly to profit. Gross margin expresses the percentage of revenue remaining after direct cost of goods sold: gross margin equals revenue minus COGS, divided by revenue. A SaaS company with 80 percent gross margins retains $0.80 of every revenue dollar to cover operating expenses, while a manufacturer with 30 percent gross margins faces much tighter operating leverage. Customer acquisition cost (CAC) divides total sales and marketing expenditure in a period by the number of new customers acquired in that same period. Customer lifetime value (LTV) estimates the total profit attributable to a customer relationship. The standard formula multiplies average revenue per user (ARPU) by gross margin and divides by the monthly churn rate. A business with $50 ARPU, 75 percent gross margin, and 2 percent monthly churn has an LTV of $1,875. The LTV:CAC ratio benchmarks unit economics health; a ratio above 3:1 is generally considered sustainable, while ratios below 1:1 indicate the business is acquiring customers at a loss. Burn rate measures monthly cash expenditure net of revenue. Cash runway equals current cash reserves divided by net monthly burn. A company with $1.2 million in the bank burning $100,000 per month has twelve months of runway. The Rule of 40 is a benchmark for SaaS health: the sum of annual revenue growth rate (as a percentage) and profit margin (as a percentage) should equal or exceed 40. High-growth companies burning cash can still pass this rule if their growth rate compensates.
History
The history behind the Churn Rate Calculator traces back through the following developments. Early economic thought centred on mercantilism, the 16th and 17th century doctrine that national wealth derived from accumulating precious metals through export surpluses and colonial extraction. Adam Smith's "Wealth of Nations" in 1776 dismantled this framework, arguing that genuine prosperity arose from specialisation, division of labour, and freely operating markets. David Ricardo extended Smith's work with the theory of comparative advantage in 1817, demonstrating mathematically that mutually beneficial trade was possible even when one country was less productive in every industry. Alfred Marshall's "Principles of Economics" published in 1890 provided the modern framework of supply and demand curves, consumer surplus, price elasticity, and marginal analysis, establishing neoclassical economics as the dominant academic paradigm for decades. The Great Depression exposed the limits of laissez-faire assumptions, and John Maynard Keynes's "General Theory of Employment, Interest and Money" in 1936 argued that private-sector aggregate demand failures required countercyclical government fiscal intervention to restore full employment, shifting the policy consensus toward active macroeconomic management. The post-World War II decades constructed mixed-economy models combining market allocation with expanded welfare states and Keynesian demand management. Milton Friedman and the Chicago School challenged this consensus from the 1960s onward, championing monetarism and arguing that stable money supply growth was superior to discretionary fiscal policy. Their influence shaped the deregulatory and privatisation policies of the Reagan and Thatcher eras in the 1980s. Behavioural economics emerged through the work of Daniel Kahneman and Amos Tversky in the 1970s and Richard Thaler in the 1980s, using psychology to demonstrate that real human decision-making deviates systematically from rational-actor models through heuristics and biases. The rise of the internet and mobile platforms in the 2000s and 2010s created a new category of platform economics, where network effects, near-zero marginal cost of digital goods, and two-sided market dynamics generated winner-take-most competitive outcomes requiring new analytical frameworks for business valuation.
Frequently Asked Questions
Sources & References
Formula
Churn Rate = (Customers Lost / Customers at Start) × 100 | Retention = 100 - Churn Rate
Churn rate is the percentage of customers lost during a period. Retention rate is its complement. Annual churn compounds monthly: Annual = 1 - (1 - Monthly Rate)^12. Average customer lifetime in months = 1 / Monthly Churn Rate.
Worked Examples
Example 1: SaaS Monthly Churn
Problem: A SaaS company starts the month with 2,000 customers and loses 80. ARPU is $59/month. Calculate churn rate and revenue impact.
Solution: Churn rate: 80/2,000 = 4.0%\nRetention rate: 96.0%\nMonthly revenue lost: 80 × $59 = $4,720\nAnnual churn rate: 1 - (0.96)^12 = 38.7%\nAvg lifetime: 1/0.04 = 25 months\nLTV: 25 × $59 = $1,475
Result: 4.0% monthly churn | $4,720/mo lost | LTV: $1,475
Example 2: Low-Churn Enterprise Product
Problem: 500 enterprise customers, 5 lost this month, $299/mo ARPU.
Solution: Churn rate: 5/500 = 1.0%\nAnnual churn: 1 - (0.99)^12 = 11.4%\nMonthly revenue lost: 5 × $299 = $1,495\nAvg lifetime: 1/0.01 = 100 months\nLTV: 100 × $299 = $29,900
Result: 1.0% monthly churn | LTV: $29,900
Frequently Asked Questions
What is customer churn rate?
Customer churn rate is the percentage of customers who cancel or stop using your product during a given period. It is calculated as: Churn Rate = (Customers Lost / Customers at Start of Period) x 100. For example, if you start the month with 1,000 customers and lose 50, your monthly churn rate is 5%. Churn is the inverse of retention — a 5% churn rate means a 95% retention rate.
What is a good churn rate for SaaS?
For B2B SaaS, a monthly churn rate of 2-3% (20-30% annually) is common for SMB-focused products. Enterprise SaaS typically sees lower churn at 0.5-1% monthly (5-10% annually). B2C subscription businesses often have higher churn at 5-7% monthly. Best-in-class companies achieve under 1% monthly churn. Net revenue retention (NRR) above 100% — where expansion revenue exceeds churned revenue — is the gold standard.
How does churn rate affect customer lifetime value?
Average customer lifetime in months equals 1 divided by the monthly churn rate. With 5% monthly churn, average lifetime is 20 months. With 2% churn, it is 50 months. LTV = Average Lifetime x Revenue Per Customer Per Month. Reducing churn from 5% to 2% increases customer lifetime by 2.5x, which directly multiplies your LTV by 2.5x. This is why churn reduction is often the highest-ROI investment for subscription businesses.
What is the difference between customer churn and revenue churn?
Customer churn counts the percentage of customers lost. Revenue churn (also called MRR churn) measures the percentage of revenue lost. They can differ significantly — if only low-paying customers churn, revenue churn is lower than customer churn. Conversely, losing a few enterprise customers can cause high revenue churn with low customer churn. Track both metrics, and also track net revenue churn which accounts for expansion revenue from remaining customers.
How do I calculate churn rate?
Churn rate is the percentage of customers who stop using your product in a given period. Monthly Churn = Customers Lost During Month / Customers at Start of Month. Annual churn can be estimated as 1 - (1 - monthly churn)^12. A 5% monthly churn equals about 46% annual churn. Track both customer churn and revenue churn separately.
Why might my result differ from another tool or reference?
Differences typically arise from rounding conventions, the specific version of a formula (for example, simple vs compound interest), or unit inconsistencies between inputs. Check that both tools are using the same formula variant and the same units. The References section links to the authoritative source behind the formula used here.
References
Reviewed by Sahil, Senior Finance & Tax Editor · Editorial policy