Customer Acquisition Cost — usually shortened to CAC — is the single number that tells you how expensive it is to win one new paying customer. If you spend $10,000 on marketing and sales in a month and land 200 new customers, your CAC is $50. That sounds simple, but most businesses calculate it wrong: they forget to include salaries, tools, creative production, and the overhead of the sales team, so the true cost is hidden in a drawer nobody opens.
This calculator divides your fully-loaded marketing and sales spend by the number of new customers acquired, then goes one step further and compares that CAC to your Customer Lifetime Value (LTV). The ratio between the two — the famous LTV:CAC ratio — is what actually tells you whether your growth engine is healthy, bleeding money, or leaving profit on the table.
How to Use
- Enter your Total Marketing & Sales Spend. Be generous: include ad spend, agency fees, creator payments, marketing software subscriptions, content production, and the salaries of everyone on the growth and sales teams who worked on acquisition during the period you are measuring. The more complete this number is, the more honest your CAC will be.
- Enter the New Customers Acquired in that same period. Count only people who actually paid you, not free-trial signups, demo requests, or newsletter subscribers. If you run a subscription business, this is new subscribers; if you run an e-commerce store, this is first-time buyers.
- Optionally fill in the Average Order Value, Purchases per Year, Average Customer Lifespan, and Gross Margin. The calculator uses these to estimate LTV so it can show your LTV:CAC ratio. If you already know your LTV from your own data, you can back into the inputs so the estimated LTV matches your known figure.
- Read the result card. The top line is your CAC in dollars. Below it is the estimated LTV, then the LTV:CAC ratio. The benchmark verdict tells you whether the ratio sits in the healthy zone.
The widely accepted benchmark is a LTV:CAC ratio of 3:1 — meaning a customer is worth three times what it costs to win them. A ratio below 1:1 means you are losing money on every customer; between 1:1 and 3:1 you are probably under-investing in growth or leaving efficiency on the table; above 5:1 you may be spending too little on acquisition and ceding market share to competitors.
The CAC and LTV Formulas
CAC comes straight from the accounting definition used by Investopedia, HubSpot, and most SaaS finance teams:
CAC = Marketing & Sales Spend ÷ New Customers Acquired
LTV is estimated with the standard margin-adjusted model:
LTV = Average Order Value × Purchases per Year × Customer Lifespan × Gross Margin
The gross-margin multiplier matters: revenue is not profit, so LTV must reflect what you actually keep after cost of goods sold. Finally:
LTV:CAC = LTV ÷ CAC
Worked example with the default inputs: $10,000 spend divided by 200 new customers gives a CAC of $50. An average order value of $50, five purchases a year, a two-year lifespan, and a 60% gross margin give an LTV of $50 × 5 × 2 × 0.60 = $300. The ratio is $300 ÷ $50 = 6.0:1 — healthy, though a little on the high side, which suggests the company could likely spend more on ads to grow faster.
What Should You Include in Marketing & Sales Spend?
A common mistake is to count only the media budget and ignore the people and tools. A defensible CAC includes:
- Ad spend on Google, Meta, TikTok, LinkedIn, and any other paid channel.
- Agency and freelancer fees — creative, landing-page design, copywriting.
- Salaries and commissions for marketers, growth engineers, SDRs, and account executives.
- Software stack — CRM, email, analytics, live chat, and retargeting tools.
- Content production — video, podcast, blog writing, and product photography.
If you strip out the team, a bootstrapped startup can show a $15 CAC that becomes $80 once salaries are loaded. Measure the fully-loaded number every quarter, not the media-only number.
Examples
Example 1 — The default SaaS scenario. A subscription startup spends $10,000 in a month and acquires 200 new customers. CAC is $50. With an AOV of $50, five purchases a year, a two-year lifespan, and a 60% gross margin, LTV is $300 and the LTV:CAC ratio is 6.0:1. The verdict: healthy, with headroom to increase spend.
Example 2 — An e-commerce store. A Shopify store spends $2,500 on ads and creators and gains 50 first-time buyers. CAC is $50. The average order value is $80, customers buy three times a year, stay 2.5 years, and the gross margin is 55%. LTV is $80 × 3 × 2.5 × 0.55 = $330, and the ratio is 6.6:1. The store can scale ad spend until the ratio drifts back toward 3:1.
Example 3 — A high-cost B2B campaign. A sales-led company spends $5,000,000 in a year and closes 10,000 new enterprise customers. CAC is $500. With an AOV of $200, ten purchases a year, a three-year lifespan, and a 50% gross margin, LTV is $3,000 and the ratio is exactly 6.0:1. Even at very large magnitudes the math holds — the engine must handle numbers in the millions without breaking.
Example 4 — The danger zone. A company spends $10,000 but only acquires 25 customers. CAC jumps to $400. If LTV is $300, the ratio is 0.75:1 — below break-even. Every new customer destroys value, and the only fixes are raising conversion, lifting prices, or cutting inefficient channels.
FAQ
What is a good CAC?
There is no universal number; a good CAC is one that leaves you a healthy margin after servicing the customer. The way to judge it is the LTV:CAC ratio, not CAC in isolation. A $50 CAC is great if LTV is $300, but terrible if LTV is $40.
What is a healthy LTV:CAC ratio?
The classic benchmark is 3:1. Below 1:1 you lose money on every customer; between 1:1 and 3:1 you are growing but not efficiently; around 3:1 is the sweet spot; above 5:1 you are likely under-spending on acquisition and competitors can out-invest you.
Should I include salaries in CAC?
Yes. A fully-loaded CAC includes the marketing and sales team's salaries, commissions, and benefits, plus software and creative costs. If you only count media spend, your CAC looks artificially low and will lead to bad budgeting decisions.
How often should I recalculate CAC?
Most mature companies measure CAC monthly and review it quarterly. Because it is a ratio of two moving numbers — spend and new customers — a single month can be noisy. Rolling three-month averages smooth out the spikes from a big product launch or a slow month.
What if I have zero new customers?
If new customers acquired is zero, CAC cannot be calculated because you would divide by zero. The calculator flags this as an error and asks you to enter a positive customer count. A period with zero new customers is a signal to investigate funnel drop-off, not a CAC number.
How does gross margin affect LTV?
LTV should reflect profit, not revenue. Multiplying by gross margin converts the top-of-funnel revenue into the dollars you actually keep after cost of goods sold. A 60% margin means only 60 cents of every revenue dollar is real contribution, so LTV is scaled down by that 0.6 factor.
Is CAC the same for B2B and B2C?
The formula is identical, but the magnitudes differ. B2B companies often have a CAC in the hundreds or thousands of dollars paired with long sales cycles and multi-year contracts, while B2C CAC can be under $20 with high churn. Always judge CAC against your own LTV and payback period rather than against an industry headline.
Disclaimer
This customer acquisition cost calculator is provided for informational purposes only and does not constitute financial, accounting, or business advice. CAC and LTV estimates depend entirely on the accuracy of the inputs you enter; LTV in particular is a forward-looking estimate that real churn, repeat purchase, and margin behavior will shift over time. Always reconcile these figures against your own books and consult a qualified finance or accounting professional before making budgeting or investment decisions.