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LTV:CAC Ratio

General

Lifetime Value to Customer Acquisition Cost Ratio

A key SaaS and e-commerce metric comparing the total revenue a customer generates over their lifetime against the cost to acquire them — a ratio of 3:1 or higher signals a healthy business.

Definition

The LTV:CAC ratio compares two fundamental business metrics: how much revenue a customer generates over their entire relationship with your business (Lifetime Value) against how much it costs to acquire that customer (Customer Acquisition Cost). Together, they determine the unit economics of your growth — whether adding customers makes you richer or poorer.

A healthy LTV:CAC ratio means your business creates more value than it spends to acquire it. An unhealthy ratio means growth is value-destructive, no matter how fast the business expands. It is the most important indicator of whether a business's growth is sustainable.

The ratio is foundational in SaaS, e-commerce, and subscription businesses, and is scrutinised by investors as a proxy for business quality.

Formula

LTV:CAC Ratio = LTV / CAC

LTV = (Average Revenue per Customer per Month × Gross Margin %) / Monthly Churn Rate

Alternatively using average customer lifespan:

LTV = Average Revenue per Customer × Gross Margin % × Average Customer Lifespan (months)

CAC = Total Sales & Marketing Spend / New Customers Acquired (in the same period)

Worked Example

A B2B SaaS company:

  • Average Monthly Revenue per Customer: ₹5,000
  • Gross Margin: 80%
  • Monthly Churn Rate: 2%

LTV = (₹5,000 × 0.80) / 0.02 = ₹4,000 / 0.02 = ₹2,00,000

In the same quarter, they spent ₹60 lakhs on sales and marketing and acquired 300 new customers.

CAC = ₹60,00,000 / 300 = ₹20,000

LTV:CAC Ratio = ₹2,00,000 / ₹20,000 = 10:1

An LTV:CAC of 10:1 is excellent — potentially indicating room to invest more aggressively in acquisition. Use the LTV:CAC ratio calculator alongside the CLV calculator and CAC calculator.

Key Things to Know

  • 3:1 is the floor, not the ceiling: 3:1 means you are profitable on customer acquisition, but there is no reason to stop optimising. The question is whether the marginal CAC for each additional customer acquired is still below LTV/3.
  • Segment your ratio: Aggregate LTV:CAC can mask huge variation. Enterprise customers may have a 20:1 ratio while SMB customers have a 1.5:1. Segmenting by customer size, channel, and geography reveals where to double down and where to cut.
  • Gross margin matters: LTV is always calculated on gross profit, not revenue. A business with 40% gross margins needs 2.5× the revenue LTV to match the LTV:CAC of a 80% margin business — this is why SaaS companies command higher valuations than e-commerce at the same revenue.
  • Churn rate is the killer: A company with a 10% monthly churn rate has an average customer lifespan of 10 months — no matter how good their CAC. The same company with 2% monthly churn has a 50-month lifespan and 5× the LTV.
  • Payback period as a complement: A 3:1 LTV:CAC ratio with a 36-month payback period requires significant working capital — you are pre-funding 3 years of customer value. Investors increasingly ask for both the ratio and the payback period.

Related Calculators

LTV:CAC Ratio Calculator →Calculate your LTV:CAC ratio instantly. Enter Customer Lifetime Value and Customer Acquisition Cost to assess business health and payback period.
Customer Lifetime Value Calculator →Calculate Customer Lifetime Value (CLV) instantly. Enter average order value, purchase frequency, customer lifespan, and gross margin to find your true CLV.
Customer Acquisition Cost Calculator →Calculate Customer Acquisition Cost (CAC) instantly. Enter your marketing and sales spend with new customers acquired to find CAC and your LTV:CAC health ratio.

Related Terms

CLVCustomer Lifetime ValueCACCustomer Acquisition CostChurn RateCustomer Churn RateROIReturn on Investment

Frequently Asked Questions

The widely cited benchmark is 3:1 — meaning for every rupee or dollar spent acquiring a customer, you should generate three in lifetime value. A ratio below 1:1 means you are losing money on each customer, which is unsustainable. A ratio above 5:1 often indicates under-investment in growth — you could likely afford to acquire more customers profitably. Most successful SaaS companies target 3:1 to 5:1.
CAC can be reduced by improving organic acquisition channels (SEO, content, referrals), increasing conversion rates at each funnel stage, reducing paid advertising waste through better targeting, improving sales efficiency, and leveraging word-of-mouth. A 20% improvement in conversion rate with the same ad spend reduces CAC by 20%. Referral programmes that turn existing customers into acquisition channels often achieve the lowest CAC.
Churn rate is the most powerful lever on LTV. LTV = Average Revenue Per Customer × Gross Margin ÷ Churn Rate. If churn rate doubles (from 5% to 10% monthly), LTV halves. Reducing churn from 5% to 2.5% monthly doubles LTV — without changing pricing or gross margin at all. This is why SaaS investors focus obsessively on net revenue retention (NRR) and customer churn.
LTV (Lifetime Value) and CLV (Customer Lifetime Value) are used interchangeably. Some practitioners distinguish between 'historical LTV' (what a cohort actually generated) and 'predictive LTV' (modelled future value). For the ratio with CAC, you want the predictive version — expected future value of an average new customer.
The CAC payback period is the number of months it takes to recover the acquisition cost from gross profit generated by the customer. LTV:CAC ratio tells you total lifetime return relative to acquisition cost; payback period tells you how long your money is tied up before you break even. A 3:1 LTV:CAC ratio with a 24-month payback period means you need to fund 24 months of customer costs before seeing profit — critical for cash flow planning.