Calculate your Customer Acquisition Cost (CAC) by dividing total sales and marketing spend by the number of new customers acquired. Compare CAC against customer lifetime value (LTV) to evaluate the sustainability and efficiency of your growth strategy.
Customer Acquisition Cost (CAC) and Customer Lifetime Value (LTV) are the foundational unit economics of any growth business. CAC measures how much you spend to acquire each new customer (all sales + marketing costs ÷ new customers). LTV measures the total revenue (or gross profit) a customer generates over their entire relationship with you. The LTV:CAC ratio reveals whether your growth is sustainable — generally, you want at least 3:1 (each customer generates 3x more value than acquisition cost) for healthy growth, with 4:1 to 5:1 indicating strong economics.
These metrics matter for several reasons: they reveal whether marketing/sales investment generates ROI; they enable comparison across channels (paid ads vs. SEO vs. partnerships have different CACs); they guide growth investment decisions (when to scale up spending); and they signal product-market fit issues when broken (high CAC + low LTV = customers don't want what you're selling enough to stick around). For investors evaluating startups, LTV:CAC is one of the most-watched metrics — companies with 1:1 or worse ratios face existential questions about business model viability.
This calculator computes CAC, LTV (using gross margin and average customer lifespan), and the LTV:CAC ratio. Use it for: monthly business health monitoring (track trends quarter over quarter), channel evaluation (which acquisition channels produce best LTV:CAC), pricing/retention decisions (raising prices or reducing churn improves LTV without changing CAC), and growth planning (how much can you spend on acquisition while maintaining healthy unit economics). Important context: early-stage companies often have unfavorable LTV:CAC (still finding product-market fit, learning sales process); mature companies in healthy markets typically achieve 3:1 to 5:1. SaaS and subscription businesses produce the most reliable LTV calculations because of predictable recurring revenue patterns.
B2B SaaS for small business: $20K marketing + $25K sales = $45K monthly spend. 100 new customers/month. $150 ARPU. 80% gross margin. 3% monthly churn (33-month lifespan). CAC = $45K / 100 = $450 LTV = $150 × 0.80 × 33 = $3,960 LTV:CAC = 8.8 (very strong) CAC Payback = $450 / ($150 × 0.80) = 3.75 months (excellent) These are strong metrics for SaaS. Healthy unit economics support aggressive growth investment. Could likely scale acquisition spend significantly while maintaining favorable economics. Action: consider scaling marketing spend (might double to $40K) since unit economics are strong enough to absorb higher CAC.
D2C consumer brand: $30K monthly ad spend, 500 new customers, $80 AOV, 30% gross margin, average customer makes 3 orders over 18 months. CAC = $30K / 500 = $60 Revenue per customer over lifetime: $80 × 3 = $240 LTV (with gross margin): $240 × 0.30 = $72 LTV:CAC = $72 / $60 = 1.2 (problematic) Just barely profitable on each customer acquisition. Most e-commerce brands in this position struggle. Without retention/repeat purchase improvement, growth is unsustainable. Action options: (1) reduce CAC through better targeting/creative, (2) increase AOV through upsells/bundles, (3) improve gross margin through pricing/sourcing, (4) increase repeat purchase rate through email marketing/loyalty. Need 30%+ improvement somewhere to reach healthy 3:1 ratio.
Enterprise B2B SaaS: $200K monthly sales + $50K marketing = $250K monthly spend. 5 new enterprise customers per month. $20K ARPU. 85% gross margin. 5-year average customer lifespan. CAC = $250K / 5 = $50,000 LTV = $20K × 0.85 × 60 = $1,020,000 LTV:CAC = 20.4 (excellent) CAC Payback = $50K / ($20K × 0.85) = 2.9 months (excellent) Enterprise SaaS unit economics: high CAC but enormous LTV, very long sales cycles. The 20:1 ratio appears excellent, but watch CAC payback (2.9 months is fast — many enterprise SaaS struggle with 12-24 month payback periods due to long sales cycles and high upfront costs). This business should likely invest aggressively in sales team expansion to capture more enterprise customers, given strong unit economics.
Use this calculator for unit economics monitoring, channel-level acquisition efficiency analysis, growth investment decisions, fundraising preparation (investors heavily weight LTV:CAC), or learning the framework for subscription business analysis.
Pair with churn-rate (drives LTV calculation), saas-metrics (broader SaaS analysis), and profit-margin (overall profitability).
Important CAC/LTV considerations:
1. **Calculate honestly.** Include ALL sales and marketing costs (salaries, tools, agency fees, content production) — not just paid ads. Honest CAC calculation often surprises (and concerns) founders.
2. **Blended vs. paid CAC.** Blended CAC includes organic acquisition (SEO, word-of-mouth) — looks better but masks paid channel inefficiency. Track both for complete picture.
3. **LTV requires accurate retention data.** Simple formulas overstate LTV by assuming customers stay forever. Use cohort-based retention analysis for accuracy. Discount future revenue for time value of money.
4. **LTV:CAC 3:1 is convention, not law.** Industry varies enormously. Software/SaaS often targets 3:1-5:1. Marketplaces sometimes acceptable at 1.5:1 if network effects compensate. Capital-intensive businesses need higher ratios.
5. **CAC payback matters for cash flow.** Even healthy LTV:CAC can produce cash flow problems if payback period is too long. SaaS standard: under 12 months payback. Slow payback requires more capital to grow.
6. **Channel-level analysis reveals where to invest.** Aggregate metrics hide channel variation. One channel might have 5:1 ratio while another has 1:1. Cut losers, scale winners.
7. **CAC inflation as you scale.** Cheapest acquisition opportunities exhausted first. Scaling typically means rising CAC as you reach broader audiences. Plan for this.
8. **Retention impacts LTV more than acquisition.** Improving retention by 10% may impact LTV by 30%+. Reducing CAC by 10% only impacts ratio by 10%. Retention investments often have higher ROI than acquisition optimization.
9. **Tie CAC to revenue cohort.** Customers acquired in different periods have different LTV. Analyze CAC against same-cohort LTV for accurate efficiency assessment.
10. **Watch for vanity metrics.** "Free" trials with 95% churn produce huge customer counts but minimal LTV. Focus on quality (paid, retaining) customers vs. raw count.
11. **B2B has long payback.** Enterprise B2B may have 24-36 month payback periods. Requires substantial growth capital. SMB B2B and consumer typically faster (6-18 months).
12. **Strategic CAC may exceed LTV temporarily.** Land-and-expand strategies, market entry, competitive defense may justify temporary unfavorable economics. But monitor — recovery plan must be clear.
Calculate customer churn rate and retention metrics.
Calculate key SaaS metrics: MRR, ARR, LTV, and CAC ratio.
Calculate asset depreciation using straight-line, MACRS, double declining balance, SYD, or units of production methods.
Model MRR, ARR, and growth projections from your SaaS pricing tiers.
Find how many units you need to sell to cover your costs.
Calculate gross, operating, and net profit margins from your revenue and costs.
CAC
$500
per customer
LTV
$1,680
per customer
LTV:CAC Ratio
3.4:1
Healthy
CAC Payback
7.1 months