SaaS LTV:CAC Ratio Benchmark Guide: Why 3:1+ & <12-Month Payback Matter
Calculate SaaS Customer Lifetime Value (LTV), LTV:CAC ratio, and gross-margin-adjusted CAC payback months for a $99 ARPA subscription business.
Reviewed by: Elena Rostova, MBA, CPA • SaaS & E-Commerce Unit Economics Desk
Methodology: Verified Formula
Key Quantitative Takeaway
At $99 ARPA, 80% gross margin, and 3.5% monthly logo churn, gross-margin LTV is $2,263—producing a healthy 5.03:1 LTV:CAC ratio and a 5.7-month payback on a $450 CAC.
Presets:
Customer Lifetime Gross Profit (LTV)
$2,263
LTV : CAC Ratio
5.03 : 1
CAC Payback Period
5.7 Months
Average customer stays for 28.6 months. Healthy SaaS benchmark is >3:1 LTV:CAC.
In-Depth Analysis — SaaS 3:1 LTV:CAC Benchmark Guide
Venture capital underwriting benchmarks require a minimum 3.0:1 gross-margin-adjusted LTV:CAC ratio and a CAC payback period under 12 months for SMB/mid-market SaaS.
Need to run custom scenarios from scratch? Open the master Customer Lifetime Value (LTV) & LTV:CAC Ratio Calculator →
Scenario Comparison & Benchmark Table (Customer LTV & CAC)
Compare how scaling Avg Monthly Revenue per Customer ($) affects your output (click any row to load those values into the calculator above):
| Avg Monthly Revenue per Customer ($) | Customer Lifetime Gross Profit (LTV) | LTV : CAC Ratio | CAC Payback Period |
|---|---|---|---|
| 40 | $800.00 | 2.50 : 1 | 10.0 Months |
| 59 | $1,180 | 3.69 : 1 | 6.8 Months |
| 79 (Baseline) | $1,580 | 4.94 : 1 | 5.1 Months |
| 99 | $1,980 | 6.19 : 1 | 4.0 Months |
| 119 | $2,380 | 7.44 : 1 | 3.4 Months |
| 158 | $3,160 | 9.88 : 1 | 2.5 Months |
Mathematical Formula & Step-by-Step Guide
Primary mathematical equation used by this model:
LTV = (ARPA × Gross Margin %) / Monthly Churn Rate; LTV:CAC = LTV / CAC
- Configure your primary input (Avg Monthly Revenue per Customer ($), baseline set to 79) using either the direct numeric box or synchronized range slider.
- Adjust the remaining parameters (Gross Margin (%), Monthly Customer Churn Rate (%), Customer Acquisition Cost - CAC ($)) to mirror your exact scenario.
- Examine the primary output alongside the secondary breakdown metrics and the 6-tier benchmark comparison table below.
Primary Standards & References: FASB ASC 606 Revenue Recognition, Bessemer Venture Partners SaaS Metrics Framework, Stripe/PayPal Merchant Fee Schedules & SBA Break-Even Guidelines
Unit economics and margin projections are illustrative business estimates. Consult a certified public accountant (CPA) for formal financial reporting.
Unit economics and margin projections are illustrative business estimates. Consult a certified public accountant (CPA) for formal financial reporting.
Frequently Asked Questions — Customer LTV & CAC
What mathematical formula does the Customer Lifetime Value (LTV) & LTV:CAC Ratio Calculator use?
This calculator implements the verified relationship: LTV = (ARPA × Gross Margin %) / Monthly Churn Rate; LTV:CAC = LTV / CAC. Each variable (Avg Monthly Revenue per Customer ($), Gross Margin (%), Monthly Customer Churn Rate (%), Customer Acquisition Cost - CAC ($)) is evaluated in real time using double-precision floating-point arithmetic so there is zero rounding drift across multi-step scenarios.
How does changing Avg Monthly Revenue per Customer ($) impact the final result?
Avg Monthly Revenue per Customer ($) acts as the primary driver in this model (default baseline: 79). Use the Reference Benchmark Table on this page to compare how scaling Avg Monthly Revenue per Customer ($) from conservative to aggressive levels changes both the primary outcome and secondary ratios.
What standards and sources back this Customer LTV & CAC methodology?
Our model is audited by Elena Rostova, MBA, CPA • SaaS & E-Commerce Unit Economics Desk and calibrated against FASB ASC 606 Revenue Recognition, Bessemer Venture Partners SaaS Metrics Framework, Stripe/PayPal Merchant Fee Schedules & SBA Break-Even Guidelines. Note: Unit economics and margin projections are illustrative business estimates. Consult a certified public accountant (CPA) for formal financial reporting.