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. As a rule of thumb, LTV:CAC of 3 or higher is healthy, under 1 means you lose money on acquisition, and payback above 18 months is cash-flow heavy for most growing SaaS businesses.
Interpret the metrics together instead of cherry-picking one. A seemingly acceptable CAC can still be dangerous if payback is long, and a great LTV:CAC ratio above 5 can mean you are actually under-spending on a channel that deserves more budget.
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?

The 3:1 ratio is the standard benchmark: 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?

SaaS benchmarks: under 12 months is excellent, 12-18 months is typical for B2B, over 24 months signals cash flow risk. E-commerce: under 6 months is strong. The payback period determines how much capital you need to scale — a 6-month payback lets you reinvest quickly; 18 months requires sustained funding.

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Workflows that use this calculator

Background on the CAC Calculator

Formula CAC Formula: How to Calculate Customer Acquisition Cost
The CAC formula divides sales and marketing spend by new customers. See how to calculate customer acquisition cost, with a worked example and variations.
Formula CAC Payback Formula
Master the CAC Payback Formula to understand how quickly your business recoups customer acquisition costs, important for evaluating marketing efficiency.
Formula Business Valuation Formula (Earnings x Multiple)
The business valuation formula multiplies normalized earnings (SDE or EBITDA) by an industry multiple. See how to set the multiple and bracket the value range.
Formula Customer Lifetime Value (LTV) Formula
The customer lifetime value formula multiplies average purchase value, frequency, and lifespan. Learn to calculate LTV and pressure-test it against churn.
Formula NPS Formula
Uncover customer loyalty insights with the NPS formula. Learn to calculate your Net Promoter Score, understand its variables, and boost your SaaS growth.
Formula Unit Economics Formula
Understand business profitability with the unit economics calculator. Estimate lifetime value from ARPU, gross margin, and lifespan, then compare it to CAC through the LTV:CAC ratio.

All resources for this calculator (23)

12 min read An Honest CAC Method for 2026 Solo Founders
Honest CAC for 2026 solo founders includes founder time, content amortization, and tool subscriptions. Method with BLS and OpenView references.
9 min read Fixing a 19-Month CAC Payback Without Cutting Spend
A 19-month CAC payback drops to 11 by raising ARPU $4 and gross margin 6 points. CAC never moves and didn't need to — here is the worked math.
10 min read How to Calculate True Customer Acquisition Cost
Calculate true CAC: most pre-seed numbers leave out the largest cost, founder time. Here is the honest formula and a fully worked solo example.

All articles

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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.