CAC Calculator

Calculate acquisition efficiency with payback and LTV:CAC context.

Result

Customer acquisition cost

$800

CAC is spend divided by customers acquired in the same period. Each customer returns $100.62 of gross profit a month, so CAC pays back in 7.95 months; over an average 25-month lifetime that is 3.14× the CAC.

Payback period

8 months

Gross profit per customer per month

$100.62

LTV (gross profit)

$2,516

LTV:CAC

3.14×

What a customer costs vs what they return

CAC against lifetime gross profit (LTV). 3× is the usual healthy line.

CAC

$800

LTV (gross profit)

$2,516

3× CAC

$2,400

General business information, not legal, tax or financial advice. The result comes only from your inputs and the published method. How we check our numbers.

How to use it

Enter sales and marketing spend, new customers acquired, monthly ARPU, gross margin, and monthly churn for the same measurement period. Include all true acquisition costs such as paid media, acquisition-focused sales labor, agencies, and tools, but exclude retention-only work if you want a clean CAC view.
Read CAC, payback period, gross profit per user per month, LTV, and LTV:CAC ratio. David Skok's SaaS Metrics 2.0 guidelines are LTV:CAC above 3 and CAC recovered within 12 months; under 1 you lose money on every customer you acquire, and the longer the payback, the more cash growth consumes.
Interpret the metrics together instead of cherry-picking one. A seemingly acceptable CAC can still be dangerous if payback is long, and a very high LTV:CAC on one channel suggests it could take more budget before its returns fall.
Use the result to set CAC caps per channel, adjust bid targets, and decide whether the next dollar should go to conversion improvement, lower spend, or retention. If CAC is fine but LTV:CAC is weak, churn is probably the more important fix than top-of-funnel volume.
Re-run monthly and by channel or campaign cohort. Track CAC, payback, and LTV:CAC side by side over time because a falling CAC can still mask worsening retention or margin erosion.

Questions people usually ask

What is a good CAC to LTV ratio?

3:1 is the most widely quoted rule of thumb: customer lifetime value should be at least 3× the cost to acquire them. At 3:1, you recover acquisition cost in roughly one-third of the customer relationship and profit the rest. Below 1:1 means you lose money on every customer. Above 5:1 often signals underinvestment in growth.

What is typically included in CAC calculation?

All sales and marketing costs to acquire a new customer: paid advertising spend, agency fees, sales team salaries and commissions (prorated to new acquisition activity), tools and software, events, content creation. Exclude account management and retention costs — those belong in LTV calculation.

How long should it take to recover CAC?

There is no single standard: published SaaS figures come from vendor surveys with different samples. This calculator warns when payback runs past 18 months, because each new customer then ties up a year and a half of gross profit before adding cash. The payback period determines how much capital you need to scale — a 6-month payback lets you reinvest quickly; 18 months requires sustained funding.

Marketing Churn & Retention Calculator
Estimate recovered customers and revenue lift from retention improvements.
Marketing A/B Test Significance Calculator
Check if your A/B test results are statistically significant and estimate sample size for reliable conclusions.
Marketing Ad Spend / ROAS Calculator
Calculate actual ROAS, break-even ROAS, profit after ad spend, target CPA, and required conversion rate for advertising campaigns.
Marketing Email Marketing ROI Calculator
Calculate projected revenue, ROI, cost per acquisition, and break-even conversion rate for email marketing campaigns.

8 min read Marketing ROI Formula: How to Calculate ROI on Marketing
Marketing ROI formula: (return − cost) ÷ cost × 100. How to calculate ROI on marketing spend with gross margin, loaded cost and CAC payback, plus examples.
9 min read Clay vs Apollo vs Instantly 2026 Compared
Clay vs Apollo vs Instantly pricing 2026: Clay Launch from $167/mo, Apollo from $49 a user, Instantly Outreach from $37.60/mo, for three different jobs.
11 min read SaaS Churn: Cohort vs Aggregate vs Net Dollar
SaaS churn three ways: aggregate churn, cohort churn and net dollar retention give different answers from one dataset. The math, and which to use when.

All articles

More in Marketing and acquisition

Know whether your marketing spend is building value or burning cash.

The Marketing and acquisition guide

Use it from code

The same calculation as a JavaScript module you can import. It runs where you import it, with no request, key or rate limit.

import { compute } from "https://aibizhub.io/engines/cac-calculator.js";

Input and output contract, TypeScript types and the guide for agents.