CAC Impact Simulator
Model the financial impact of reducing your Customer Acquisition Cost. Calculates LTV/CAC ratio change and payback period improvement.
About this calculator
The CAC Impact Simulator on NumberCals is a free, mobile-friendly tool for anyone needing to model the financial impact of reducing your customer acquisition cost. calculates ltv/cac ratio change and payback period improvement. Enter your values in the form below and the result is computed instantly — no sign-up, no installation, no waiting.
Formula used
LTV = ARPU·Margin/Churn; LTV/CAC = LTV÷CAC; Payback = CAC ÷ (ARPU·Margin)
What you'll need
- Current CAC (e.g. 500)
- Target (Reduced) CAC (e.g. 350)
- ARPU (monthly) (e.g. 100)
- Gross Margin (%) (e.g. 80)
- Monthly Churn (%) (e.g. 3)
- New Customers per Month (e.g. 100)
What you'll get
- Customer LTV
- Current LTV/CAC Ratio
- New LTV/CAC Ratio
- Current Payback Period (months)
- New Payback Period (months)
- Monthly CAC Savings
- Annual CAC Savings
Frequently Asked Questions
What's a healthy LTV/CAC? +
The SaaS rule of thumb: 3× or higher is healthy, 1× or lower is unsustainable. Anything 5×+ may indicate under-investment in growth.
What's a good payback period? +
12 months for SMB SaaS, 18 months for mid-market, up to 24 for enterprise. Faster payback = less capital required to scale.