Find your customer acquisition cost from spend and new customers — free, instant.
How much does each new customer really cost you? Our free Customer Acquisition Cost Calculator divides your total marketing spend by the number of new customers it produced — giving you CAC, the number that decides whether your growth is profitable or just expensive.
Customer acquisition cost is the fully-loaded price of winning one customer: ad spend, agency fees, salaries, tools, and creative, divided by new customers acquired. Spend $12,000 to win 300 customers and your CAC is $40 — every customer must eventually return more than $40 for the business to make sense.
Enter your total marketing spend and new customer count — the $12,000 / 300 defaults show the classic calculation — and get your CAC with the lifetime-value target it needs to beat.
CAC is the unit economics of growth itself. Every business buys customers — with ads, content, sales teams, or discounts — and CAC states the price per unit. A $40 CAC is neither good nor bad in isolation; it is good if customers return $200 over their lifetime and fatal if they return $30. CAC only means something next to customer lifetime value (LTV).
The classic benchmark is the LTV:CAC ratio: lifetime value divided by acquisition cost. At 3:1 or better, growth funds itself — each $40 customer returns $120+, leaving room for product costs, overhead, and profit. Near 1:1, you are churning dollars: revenue arrives but margin never does. Below 1:1, every new customer destroys value, and “scaling” just scales the losses. Investors scrutinize this ratio above almost any other startup metric.
Getting CAC right means counting fully-loaded spend. Teams routinely understate it by counting only ad spend while ignoring the salaries of the marketers running the ads, the agency retainer, the creative production, and the marketing software. True CAC uses the whole sales-and-marketing cost center — which is why the fully-loaded number often shocks founders who thought they were acquiring customers cheaply.
The time window matters too. Spend in January may produce customers who convert in March — mismatched periods distort CAC in both directions. Use consistent cohort windows (spend and the customers that spend actually produced), and separate blended CAC (all channels averaged) from paid CAC (paid channels only) — the blend hides which channels are efficient and which are burning money.
Key terms:
Use fully-loaded spend (ads + salaries + agencies + tools) over the same period the customers were won. New customers must be greater than zero.
A candle brand spends $12,000 in Q1 (ads $8,000, freelancer $2,500, tools $1,500) and acquires 300 new customers. CAC?
Fully-loaded accounting is the honest version — ad-only CAC would have falsely read $26.67.
Monthly sales and marketing: $60,000. New customers: 120. LTV: $900.
A 1.8:1 ratio with an 8-month payback is survivable with funding, but it cannot self-fund growth.
Paid search: $8,000 spend, 200 customers → $40 CAC. Organic/content: $4,000 spend, 100 customers → $40 CAC. Blended: $12,000 ÷ 300 = $40.
Blended CAC hides channel truth — always split paid vs. organic before deciding where to invest.
A meal-kit startup: $12,000 monthly marketing, 300 new customers → $40 CAC, LTV $160 (4:1 ratio). The CEO wants to triple spend. Before approving, the CMO models saturation: at 3× spend, marginal CAC on the extra dollars runs $65 (new audiences convert worse). Blended CAC rises to ~$48 — still under the $53 ceiling for 3:1. Approved, with a kill-switch: if blended CAC crosses $53, spend snaps back. CAC math turned a gut decision into a bounded experiment.
Second scenario: a law firm’s PPC: $12,000 spend, 300 leads but only 30 signed clients. Marketing CAC per lead is $40 — but true CAC per client is 12,000 ÷ 30 = $400. With $2,500 average case value, the ratio is 6.25:1 — wildly profitable, and the firm was under-spending because it judged the $40 lead number instead of the $400 client number. Always divide by customers, not leads.
Third: a mobile game: $12,000 on install ads, 300 paying players → $40 CAC against $25 average LTV — upside down. The fix isn’t cheaper ads; it’s monetization: raising LTV to $130 via battle passes flips the ratio to 3.25:1. When CAC exceeds LTV, the product — not the marketing — is usually the problem.
Fourth: a B2B marketplace: $12,000 spend, 300 new customers → $40 CAC. But 40% churn in 90 days, so effective LTV is only $70 — ratio 1.75:1. Cutting onboarding friction lifts retention, LTV climbs to $140, ratio hits 3.5:1. Retention is a CAC lever: keeping customers is cheaper than re-acquiring them.
Typical CAC ranges: e-commerce $30–70; SaaS $200–600+ (SMB) and thousands (enterprise); mobile apps $2–10 per install but $30–80 per payer; local services $50–300. The 3:1 rule holds across most: below it, growth consumes capital; far above 5:1, you may be under-investing in growth. Payback targets: under 12 months for SMB SaaS, under 6 for e-commerce.
Why CAC rises with scale: the cheapest customers come first — friends, fans, high-intent searchers. Each new audience tier converts worse, so marginal CAC climbs as spend scales. Smart teams track marginal CAC per budget increment and stop scaling a channel when its marginal ratio falls below target, even while blended CAC still looks fine.
Edge cases and pro tips: freemium models need CAC per paying customer, not per signup — dividing by free users massively understates cost. Marketplaces have two CACs (supply and demand) — track both. Referral and word-of-mouth customers still carry CAC: the discounts, referral bonuses, and brand spend that earned them. And CAC payback in months = CAC ÷ monthly gross profit per customer — the cash-flow companion to the LTV ratio that finance teams actually manage to.
When CAC is the wrong lens: in land-grab markets, temporarily accepting 1.5:1 to capture share can be rational — if retention later lifts LTV. For network-effect products, early users raise everyone’s LTV, so static CAC math understates value. And brand building has no clean per-customer cost — judge it on aided awareness and blended CAC trend, not campaign-level division. CAC prices the transaction; strategy sometimes prices the future.
The LTV:CAC ratio tells you growth is profitable; the payback period tells you whether you can afford it. Payback = CAC ÷ monthly gross profit per customer. At $40 CAC and $25 monthly gross profit, payback is 1.6 months — cash recycles almost immediately. At $500 CAC and $60 monthly gross profit, payback stretches to 8.3 months — every new customer is an 8-month loan your balance sheet must fund. Two companies with identical 3:1 ratios can have wildly different cash needs.
This is why high-growth startups raise capital: not because unit economics fail, but because payback timing starves cash. A useful rule: payback under 12 months lets growth self-fund with discipline; beyond 18 months, growth consumes working capital faster than operations generate it. Model payback alongside the ratio in every scaling plan, and set a payback ceiling the way you set a CAC ceiling.
Improve payback from both ends. Lower CAC through better conversion and cheaper channels; accelerate gross profit through annual prepay plans (cash upfront collapses payback to near zero), onboarding that drives fast time-to-value, and expansion revenue in the first 90 days. Annual billing is secretly a CAC-payback weapon: a $480 annual plan against $40 CAC pays back on day one.
Track payback by cohort, not as a company average. January’s cohort may pay back in 6 months while June’s takes 14 — channel mix, seasonality, and onboarding changes all move it. Cohort payback curves reveal whether your economics are improving or quietly deteriorating beneath a stable blended ratio.
CAC = total sales and marketing spend / new customers acquired. $12,000/300 = $40. Use fully-loaded spend (ads + salaries + agencies + tools); divide by customers not leads; target LTV:CAC >= 3:1; watch payback period and marginal CAC when scaling. Source: Sigma Calculator, Customer Acquisition Cost Calculator, https://sigmacalculator.net/digital-marketing-calculators/customer-acquisition-cost-calculator/
Cite this page as: Customer Acquisition Cost Calculator, Sigma Calculator, https://sigmacalculator.net/digital-marketing-calculators/customer-acquisition-cost-calculator/
Last updated: October 12, 2026