# What is my CAC?

Computes customer acquisition cost (CAC): what you spent on sales and marketing in a period ÷ the new customers you won in it, with the marketing and sales cost per customer.

- Page: https://www.acalculator.org/finance/cac-calculator
- JSON spec: https://www.acalculator.org/finance/cac-calculator.json
- Version: 1421e1a00ca2

## Default answer

Example with the default inputs (Marketing costs $30,000.00, Sales costs $20,000.00, New customers 125): $50,000.00 of sales and marketing for 125 new customers is a CAC of $400.00.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| marketing | Marketing costs | What you spent on marketing in the period: ads, content, tools and marketing pay. |
| sales | Sales costs | What you spent on sales in the period: sales pay, commissions and tools. |
| customers | New customers | The new customers you won in the same period. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| cac | Customer acquisition cost (CAC) | (Marketing costs + sales costs) ÷ new customers. |
| total | Sales and marketing costs | Marketing costs + sales costs. |
| marketingPer | Marketing cost per new customer | Marketing costs ÷ new customers. |
| salesPer | Sales cost per new customer | Sales costs ÷ new customers. |

## Method

CAC = (marketing costs + sales costs) ÷ new customers; marketing cost per customer = marketing costs ÷ new customers; sales cost per customer = sales costs ÷ new customers.

## Assumptions

- The costs and the new customers cover the same period.
- New customers are first-time buyers won in the period; returning customers do not count.
- Arithmetic is exact on the typed decimals; money shows to the cent, halves up.

## Worked examples

1. marketing = $30,000.00, sales = $20,000.00, customers = 125 gives cac = $400.00, total = $50,000.00, marketingPer = $240.00, salesPer = $160.00. Source: OpenStax, Principles of Marketing, 2.4 Marketing Plan Progress Using Metrics (CAC is the cost of sales and marketing efforts divided by the number of new customers). https://openstax.org/books/principles-marketing/pages/2-4-marketing-plan-progress-using-metrics.
2. marketing = $10,000.00, sales = $0.00, customers = 20 gives cac = $500.00, total = $10,000.00. Source: OpenStax, Principles of Marketing, 2.4 Marketing Plan Progress Using Metrics (CAC is the cost of sales and marketing efforts divided by the number of new customers). https://openstax.org/books/principles-marketing/pages/2-4-marketing-plan-progress-using-metrics.
3. marketing = $8,345.67, sales = $4,000.00, customers = 7 gives cac = $1,763.67, total = $12,345.67. Source: OpenStax, Principles of Marketing, 2.4 Marketing Plan Progress Using Metrics (CAC is the cost of sales and marketing efforts divided by the number of new customers). https://openstax.org/books/principles-marketing/pages/2-4-marketing-plan-progress-using-metrics.

## FAQ

### What is CAC?

CAC, customer acquisition cost, is what it costs a business on average to win one new customer. It counts the money spent on sales and marketing in a period against the new customers won in the same period.

### How do I calculate customer acquisition cost?

Add up your sales and marketing costs for the period and divide by the number of new customers. $30,000 of marketing and $20,000 of sales for 125 new customers is (30,000 + 20,000) ÷ 125 = $400 per customer.

### What costs go into CAC?

Everything you spend to win customers: advertising, content, events, marketing and sales software, and the pay and commissions of your marketing and sales staff. Leave out the cost of serving customers you already have.

### Which customers count?

Only new customers: people or businesses who bought from you for the first time in the period. Returning customers, free sign-ups and leads who have not bought yet do not count.

### What is a good CAC?

A good CAC is well below what a customer is worth to you. Compare it with your customer lifetime value: if winning a customer costs more than the profit they bring, each new customer loses money.

### Why does my CAC change from month to month?

Spending often wins customers later than it is paid: an ad seen in March may win a customer in May. Measuring over a longer period, such as a quarter, makes that delay matter less.

## Sources

- OpenStax, Principles of Marketing, 2.4 Marketing Plan Progress Using Metrics: customer acquisition cost is calculated by adding up the cost of sales and marketing efforts and dividing by the number of new customers. https://openstax.org/books/principles-marketing/pages/2-4-marketing-plan-progress-using-metrics (retrieved 2026-10-18)