FREE SAAS METRICS TOOL
LTV CAC Ratio Calculator
Compare LTV with CAC, target-ratio headroom, and payback.
SAAS UNIT ECONOMICS
Compare lifetime value with acquisition cost
Planning guidance only. A 3:1 ratio is a common heuristic, not a universal target. Consider payback timing, cash runway, retention quality, and growth efficiency alongside this result.
THE BASICS
What is an LTV:CAC ratio calculator?
An LTV:CAC ratio calculator compares customer lifetime value with customer acquisition cost. It helps founders test whether the economic value of a customer is proportionate to the cost of winning that customer.
Build the numerator with the LTV Calculator and the denominator with the CAC Calculator. Use the same customer segment and compatible time periods.
LTV:CAC ratio formulas
LTV:CAC ratio = gross-profit customer LTV ÷ fully loaded CACMaximum CAC at target = customer LTV ÷ target ratioCAC payback months = CAC ÷ monthly gross profit per customerA ratio of 3.00:1 means the estimated gross-profit LTV is three times the acquisition cost. It does not mean that cash is received three times faster.
How to interpret the ratio
Below 1:1, acquisition cost exceeds estimated lifetime value. Between 1:1 and 3:1, the customer may create value but offers less cushion for overhead, uncertainty, and capital costs. Ratios from 3:1 to 5:1 are commonly treated as a practical planning range.
Above 5:1 can indicate strong economics, but investigate whether LTV is optimistic, CAC is incomplete, or growth is being constrained by underinvestment. These bands are diagnostic prompts—not universal verdicts.
SaaS LTV:CAC example
With $2,000 gross-profit LTV and $600 fully loaded CAC, the ratio is 3.33:1. At $80 monthly gross profit per customer, CAC payback is 7.5 months.
| Result | Metric | Result |
|---|---|---|
| Gross-profit LTV | $2,000.00 | |
| Fully loaded CAC | $600.00 | |
| LTV:CAC ratio | 3.33:1 | |
| CAC as share of LTV | 30.00% | |
| Value after CAC | $1,400.00 | |
| Maximum CAC at 3:1 | $666.67 | |
| CAC payback | 7.50 months |
Use ratio and payback together
The ratio measures total expected unit economics; payback measures timing. A compelling ratio with a long payback period can still strain a bootstrapped company’s cash. Revisit churn assumptions in the Churn Calculator and pricing or gross margin in the SaaS Pricing Calculator.
Segment the calculation by plan, channel, geography, and customer size. Blended averages can hide a profitable segment subsidizing an unprofitable one.
COMMON QUESTIONS
LTV and CAC questions
What is the LTV:CAC ratio?
The LTV:CAC ratio compares the gross-profit value expected from an average customer with the sales and marketing cost required to acquire that customer.
Is a 3:1 LTV:CAC ratio always good?
No single ratio is right for every company. A 3:1 ratio is a common planning reference, but cash constraints, payback speed, confidence in LTV, market maturity, and growth goals all change the appropriate target.
Should I use revenue LTV or gross-profit LTV?
Use gross-profit LTV when comparing with CAC. Revenue LTV ignores the direct costs required to deliver the service and can overstate the economics.
Should CAC be fully loaded?
Use fully loaded CAC for strategic unit-economics decisions. Include the sales and marketing people, programs, tools, agencies, and other acquisition costs attributable to the same customer group.
Why does CAC payback matter if my ratio is healthy?
LTV can arrive over years while acquisition spending happens now. Payback shows how quickly gross profit recovers CAC and therefore adds crucial cash-timing context to the ratio.
Can a very high LTV:CAC ratio be a warning?
Sometimes. It may reflect excellent economics, but it can also indicate understated CAC, optimistic LTV, or underinvestment in acquisition that is limiting otherwise efficient growth.