Customer Acquisition Cost Calculator
Calculate CAC from total marketing spend and new customers acquired. Enter values for instant results with step-by-step formulas.
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Add all marketing and sales expenses for a given period, then divide by the number of new customers acquired during that same period. The result is your average cost to acquire one new customer.
Last reviewed: December 2025
Worked Examples
Example 1: SaaS Company CAC
Example 2: E-commerce Business
Background & Theory
The Customer Acquisition Cost 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 Customer Acquisition Cost 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
Formula
CAC = (Total Marketing Spend + Total Sales Spend) / New Customers Acquired
Add all marketing and sales expenses for a given period, then divide by the number of new customers acquired during that same period. The result is your average cost to acquire one new customer.
Worked Examples
Example 1: SaaS Company CAC
Problem: A SaaS company spends $50,000/month on marketing and $30,000/month on sales, acquiring 200 new customers. Their average customer LTV is $1,200.
Solution: Total Spend = $50,000 + $30,000 = $80,000\nCAC = $80,000 / 200 = $400\nLTV:CAC = $1,200 / $400 = 3.0:1
Result: CAC: $400 | LTV:CAC Ratio: 3.0:1 โ Healthy
Example 2: E-commerce Business
Problem: An online store spends $15,000 on ads and $5,000 on email marketing, gaining 500 new customers.
Solution: Total Spend = $15,000 + $5,000 = $20,000\nCAC = $20,000 / 500 = $40
Result: CAC: $40 per customer
Frequently Asked Questions
What is Customer Acquisition Cost (CAC)?
Customer Acquisition Cost (CAC) is the total cost of acquiring a new customer, including all marketing and sales expenses. It is calculated by dividing total acquisition spending by the number of new customers gained in a specific period. For example, if you spend $10,000 on marketing and sales in a month and acquire 100 new customers, your CAC is $100. CAC is a critical metric for understanding business unit economics and profitability.
How is customer lifetime value (CLV) calculated?
Simple CLV = Average Purchase Value * Purchase Frequency * Customer Lifespan. For subscription models: CLV = Average Monthly Revenue per Customer / Monthly Churn Rate. For example, if a customer pays 50 dollars/month and your monthly churn is 5%, CLV = 50/0.05 = 1,000 dollars. CLV should be at least 3 times your customer acquisition cost.
How do I calculate customer acquisition cost (CAC)?
CAC = Total Sales and Marketing Expenses / Number of New Customers Acquired in that period. Include all related costs: advertising, salaries, tools, commissions, and overhead. CAC payback period = CAC / Monthly Gross Margin per Customer. A payback period under 12 months is generally healthy for SaaS businesses.
Can I use Customer Acquisition Cost Calculator on a mobile device?
Yes. All calculators on NovaCalculator are fully responsive and work on smartphones, tablets, and desktops. The layout adapts automatically to your screen size.
Is my data stored or sent to a server?
No. All calculations run entirely in your browser using JavaScript. No data you enter is ever transmitted to any server or stored anywhere. Your inputs remain completely private.
How do I get the most accurate result?
Enter values as precisely as possible using the correct units for each field. Check that you have selected the right unit (e.g. kilograms vs pounds, meters vs feet) before calculating. Rounding inputs early can reduce output precision.
References
Reviewed by Daniel Agrici, Founder & Lead Developer ยท Editorial policy