The LTV to CAC ratio divides the lifetime value of a customer by what it cost to acquire them. A ratio of 3:1 means each customer is worth three times what you paid to win them. It is the most common shorthand for whether a business's growth is healthy.
What is a good LTV:CAC ratio?
| Ratio | What it usually means |
|---|---|
| Below 1:1 | Each new customer destroys value. Stop scaling and fix the unit economics. |
| 1:1 to 3:1 | Profitable per customer but thin. Overheads and churn surprises can wipe it out. |
| 3:1 to 5:1 | The commonly cited healthy range. Room to grow and to absorb mistakes. |
| Above 5:1 | Often a sign you are under-investing in growth and could acquire more customers profitably. |
The 3:1 rule is a convention from venture-backed SaaS, not a law. A business with low overheads can thrive at 2:1; one with heavy fixed costs may need 4:1. Treat it as a starting benchmark.
Calculating LTV correctly
For subscriptions, lifespan comes from churn: average lifetime in months = 1 / monthly churn rate. With 4% monthly churn, the average customer stays 25 months.
The most important rule: use gross profit, not revenue. A $600 revenue LTV at 40% margin is $240 of real value. Comparing $600 to a $200 CAC shows a comfortable 3:1; the honest ratio is 1.2:1. Calculate yours with the LTV calculator, and work out churn with the churn rate calculator.
Calculating CAC correctly
"Total" is where most ratios get flattered. Paid CAC (ad spend only) is useful for channel decisions, but fully loaded CAC also includes marketing salaries, agency fees, tools, sales commissions and content production. Investors and lenders usually want the fully loaded number. The CAC calculator shows both.
Worked example
A B2B software tool charges $49 a month at 85% gross margin with 3% monthly churn. Last quarter it spent $36,000 on ads and $24,000 on marketing salaries and tools, and won 400 new customers.
- Lifetime: 1 / 0.03 = 33.3 months
- LTV: $49 x 33.3 x 0.85 = $1,388
- Paid CAC: $36,000 / 400 = $90 - ratio 15.4:1
- Fully loaded CAC: $60,000 / 400 = $150 - ratio 9.3:1
- CAC payback: $150 / ($49 x 0.85) = 3.6 months
That ratio is high enough to suggest the company could spend more on acquisition - though a 33-month lifetime estimated from a young customer base deserves caution.
Do not forget payback time
LTV:CAC ignores timing. Two businesses can both have 3:1, but one earns back CAC in 4 months and the other in 30. The second needs far more cash to grow. Track CAC payback months alongside the ratio:
How to improve LTV:CAC
- Reduce churn. Better onboarding, quicker time to value, and win-back campaigns. Because lifetime = 1 / churn, cutting churn from 5% to 4% lengthens average lifetime by 25%.
- Raise prices or average order value. It raises LTV with no change in CAC.
- Shift budget to efficient channels. Calculate CAC per channel; blended averages hide channels that lose money.
- Improve conversion rates on landing pages and trials - the same spend wins more customers.
- Expand existing customers with upgrades and add-ons.
Frequently asked questions
Is a 3:1 LTV to CAC ratio good?
Yes, 3:1 is the most commonly cited healthy ratio. Whether it is enough depends on your overheads and how fast you recover CAC.
Can LTV:CAC be too high?
A very high ratio (above about 5:1) often means you could profitably spend more on acquisition and grow faster.
Should LTV use revenue or profit?
Gross profit. Revenue-based LTV overstates customer value and leads to overspending on acquisition.