# Free customer acquisition cost calculator

> Free customer acquisition cost calculator. Add your marketing and sales spend and new customers to get your CAC and how many months it takes to earn back.

Free tool by Reuily · Updated 2026-10-15

Canonical: https://reuily.com/tools/customer-acquisition-cost-calculator

Find what each new customer costs you, and how many months it takes to earn it back.

The interactive tool is at https://reuily.com/tools/customer-acquisition-cost-calculator. To do it yourself:

1. Add up your marketing and sales spend for a period.
2. CAC = total spend ÷ new customers won in the same period.
3. Payback in months = CAC ÷ (monthly revenue per customer × gross margin).

## How to use the CAC calculator

1. **Enter your marketing spend.** Include ads, tools and content for one period, such as a month or a quarter.
2. **Add your sales spend if you have one.** Salaries, commission and sales tools all count.
3. **Enter the new customers you won** in that same period.
4. **Add revenue and margin to see payback.** With monthly revenue per customer and your gross margin, the calculator shows how many months a customer takes to pay back what you spent to win them.

## How do you calculate customer acquisition cost?

> CAC = (marketing spend + sales spend) ÷ new customers

For example, if you spend $12,000 on marketing and $8,000 on sales in a quarter and win 40 customers, your CAC is $20,000 ÷ 40 = **$500**.

## What is the CAC payback period?

Payback is how long a customer takes to earn back what you spent to win them.

> Payback in months = CAC ÷ (monthly revenue per customer × gross margin)

With a CAC of $500, customers paying $99 a month and an 80% gross margin, each customer brings in about $79 of gross profit a month, so you earn your $500 back in about **6.3 months**.

## What is a good CAC?

A good CAC is one your customers pay back comfortably. Two common checks:

- **Payback under 12 months** is a common target for subscription businesses.
- **Lifetime value at least three times CAC** leaves room for everything else the business pays for.

If your CAC is too high, look first at the leads that never buy. Qualifying leads before a sales call stops your team spending time on people who were never a fit.

## How to lower your customer acquisition cost

- **Ask better questions on your lead form.** Budget, timeline and company size show you who is ready before anyone books a call.
- **Follow up fast.** Leads contacted quickly convert more often than leads who wait a day.
- **Measure by channel.** Work out CAC for each channel separately, so you can move spend to the ones that work.

## Frequently asked questions

### What costs go into CAC?

Everything you spend to win new customers in the period: ads, marketing tools, content, events, and the salaries and commission of the people who sell. Leave out costs of serving customers you already have.

### Should I include salaries?

For a full picture, yes. Some teams also track a paid CAC with ad spend only, which is useful for comparing channels.

### What period should I use?

Use a month or a quarter, and count customers won in the same period. If your sales cycle is long, a quarter gives a steadier number.

### What is the difference between CAC and cost per lead?

Cost per lead counts everyone who filled in your form. CAC counts only the people who bought, so it is always higher. The cost per lead calculator works out both.

### Is my data saved?

No. The calculator runs in your browser, and the numbers you enter are not sent anywhere or saved.

## Templates that go with it

- [Lead Generation Form](https://reuily.com/templates/lead-generation-form): Asks for budget, timeline and work email, and sorts each lead as hot, warm or not a fit.
- [Quote Request Form](https://reuily.com/templates/quote-request-form): Collects the details you need to price a job before the first call.