PPC Profitability Toolkit
Competitor calculators usually stop at ROAS. This toolkit combines ROAS with CAC, LTV, MER, and target CPA so decisions are based on unit economics.
Quick definition: this page is a central planning hub for paid media unit economics, including acquisition cost, lifetime value, blended efficiency, and payback speed.
Written by: Priya Malhotra (Content Strategist)
Reviewed by: Rahul Verma (Data QA Reviewer)
Published: February 2026 | Last reviewed: February 2026
Read our Editorial Policy, Methodology, and Data Sources.
Core Metrics in One View
| Metric | Formula | Interpretation |
|---|---|---|
| ROAS | Revenue / Ad Spend | Revenue efficiency of media spend |
| Break-even ROAS | 1 / Contribution Margin | Minimum ROAS required to avoid losses |
| CAC | Ad Spend / New Customers | Cost to acquire one paying customer |
| LTV:CAC | Lifetime Value / CAC | 3:1+ is generally healthy for scale |
| MER | Total Revenue / Total Marketing Spend | Measures blended channel efficiency |
| Target CPA | AOV * Margin * Target Conversion Rate | Max CPA to hit profit target |
Decision Support Playbook
Use this sequence before increasing spend: validate break-even ROAS, confirm CAC payback window, then check blended MER.
- Scale when ROAS is 20%+ above break-even and LTV:CAC is greater than 3.
- Hold when ROAS is near break-even and conversion rate is unstable.
- Pause when ROAS is below break-even for 7-14 days despite creative and landing page iteration.
Use-Case Calculators
CAC Calculator
Track acquisition cost per new customer.
LTV Calculator
Estimate customer value across retention windows.
MER Calculator
Monitor blended channel efficiency.
CAC Payback Calculator
See how fast acquisition spend returns.
Break-even ROAS
Find minimum return required before scaling.
Target CPA
Set cost-per-acquisition guardrails for paid channels.
Google Shopping ROAS
Plan feed-based campaign profitability.
Lead Gen CPL ROAS
Convert CPL assumptions into revenue outcomes.
Cluster Navigation
Use this loop for weekly planning: learn the metric, benchmark it, optimize execution, then validate profitability.
Templates for Practitioners
Download scenario planners and budget models for weekly performance reviews and stakeholder reporting.