Customer Acquisition Cost Formula Guide With Free CAC Calculator, Cost Breakdown, Payback Period, LTV:CAC Ratio, Target CAC, Examples, and Checklist
Learn the customer acquisition cost formula and calculate CAC locally from marketing and sales costs and new customers. Model payback, LTV:CAC and target gaps.
Calculate, compare, visualize, and export
Local scenario history
Eight microlearning boxes
Start with the denominator
Rates are only meaningful when the denominator matches the business question: sessions, users, delivered emails, spend, customers, or observations.
Separate revenue from profit
ROAS uses revenue relative to ad spend, while ROI should reflect costs and the contribution or profit basis you intend to measure.
Statistical significance is not business significance
A small difference can be statistically detectable yet economically unimportant; effect size and decision value still matter.
Power depends on the effect you want to detect
Smaller minimum detectable effects generally require more observations to reach the same statistical power.
Finite populations can reduce survey sample needs
When sampling without replacement from a known finite population, finite-population correction can lower the required completed sample.
Attribution assumptions drive marketing metrics
CAC and marketing ROI depend on which costs, customers and revenue you attribute to the measured period or campaign.
Confidence intervals communicate uncertainty
A point estimate such as conversion lift is more useful when paired with a range of plausible effects.
Scenario tools support decisions, not certainty
Use sensitivity analysis, representative data and domain constraints before committing budget or making product decisions.
Knowledge challenge
Online checklist
Related ready pages
Frequently asked questions
Is this page free to use?
Yes. No email, phone number, signup or payment is required.
Does the main calculation run locally?
Yes. The interactive calculations are designed to run in your browser.
Can I load a worked example?
Yes. Every page includes a Load worked example control.
Can I export the result?
Yes. You can download the primary summary and a CSV report.
Are statistical and marketing outputs guarantees?
No. They depend on assumptions, data quality, attribution, model choice and the scope of the implemented formulas.
Method, scope, and limitations
These calculations are educational and planning aids. Results depend on attribution, sampling design, independence assumptions, measurement definitions, cost allocation and data quality. Statistical approximations are not a substitute for an experiment design review when stakes are high.