ShadTools

LTV to CAC Calculator

Calculate Customer Lifetime Value (LTV), Customer Acquisition Cost (CAC), LTV:CAC ratio, and CAC payback period.

LTV : CAC Ratio
4x
Healthy (3x – 5x)
3,200Customer Lifetime Value (LTV)
800Customer Acquisition Cost (CAC)
10 moCAC Payback Period
40 moAvg Customer Lifetime

Unit Economics Breakdown

Gross Lifetime Revenue:4,000
Cost to Serve (COGS 20%):-800
Gross Profit LTV:3,200
Acquisition Cost (CAC):-800
Net Profit per Customer:2,400 (300% ROI)

Churn Sensitivity Analysis

Monthly ChurnLifetimeLTVLTV : CAC
1%100 mo8,00010x
2%50 mo4,0005x
2.5%40 mo3,2004x
3%33.3 mo2,6673.3x
4%25 mo2,0002.5x

Standard benchmark for sustainable SaaS and subscription businesses.

Evaluate the sustainability and profitability of your customer acquisition model with comprehensive unit economics and churn sensitivity analysis.

Formulas & Methodology

  • Customer Lifespan (Months): 1 ÷ Monthly Churn Rate
  • Gross Lifetime Revenue: Monthly ARPU × Customer Lifespan
  • Customer Lifetime Value (LTV): (Monthly ARPU × Gross Margin %) ÷ Monthly Churn Rate
  • LTV : CAC Ratio: LTV ÷ CAC
  • CAC Payback Period (Months): CAC ÷ (Monthly ARPU × Gross Margin %)
  • Net Unit Profit: LTV - CAC

Worked Acceptance Example

For a SaaS product with:

  • Monthly ARPU: $100.00
  • Gross Margin: 80%
  • Monthly Churn Rate: 2.5%
  • CAC: $800.00

The calculations are:

  1. Customer Lifespan: 1 ÷ 0.025 = 40.0 months
  2. Gross Lifetime Revenue: $100 × 40 = $4,000.00
  3. LTV: $4,000 × 0.80 = $3,200.00
  4. LTV:CAC Ratio: $3,200 ÷ $800 = 4.00x (Healthy)
  5. CAC Payback Period: $800 ÷ ($100 × 0.80) = 10.0 months

Frequently Asked Questions

What is a good LTV to CAC ratio?+

A 3:1 (3x) to 5:1 (5x) LTV:CAC ratio is widely considered the gold standard benchmark for subscription and SaaS businesses. A ratio below 1x loses money on every acquisition, while a ratio above 5x often means you are under-investing in marketing and leaving growth on the table.

How is Customer Lifetime Value (LTV) calculated?+

Customer Lifetime Value is calculated as (Monthly ARPU × Gross Margin %) ÷ Monthly Churn Rate. This accounts for revenue, gross margin costs to deliver service, and the average customer retention lifespan.

What is CAC Payback Period?+

CAC Payback Period is the number of months required for a customer's gross profit to fully pay back the cost to acquire them (CAC ÷ [Monthly ARPU × Gross Margin %]). An ideal SaaS payback period is under 12 months.

How does churn rate affect LTV?+

Churn rate is inversely proportional to customer lifetime (Lifetime = 1 ÷ Churn Rate). Halving your monthly churn rate from 4% to 2% doubles the average customer lifespan and doubles total LTV.

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