CAC Calculator
CAC shows how much you spend to acquire one paying customer. Track it weekly with ROAS and LTV:CAC.
Quick answer: CAC equals total ad spend divided by new customers acquired in the same period.
Formula
CAC = Total Ad Spend / New Customers
Example: $6,000 spend / 120 new customers = $50 CAC.
Decision Thresholds
- Scale when CAC is below your target threshold and payback window is acceptable.
- Hold when CAC drifts but still stays inside margin guardrails.
- Pause or rework when CAC exceeds target for 7-14 days after optimizations.
What CAC Means for Decision-Making
CAC is your acquisition price per customer, not your profitability outcome. A low CAC can still be unprofitable if margin is weak, and a high CAC can still be acceptable if LTV and payback are strong. Use CAC with ROAS and MER before budget changes.
How to Evaluate Your Result
- Compare CAC to gross profit per customer, not only top-line revenue.
- Track rolling 7-day and 30-day CAC to avoid reacting to short attribution noise.
- Validate that CAC trends stay healthy after spend increases, not just before scaling.
Realistic Business Scenarios
- DTC eCommerce: CAC rises during promos, but repeat purchase lifts LTV and keeps scaling viable.
- SaaS trial funnel: paid CAC is high early, but acceptable once onboarding improves payback below 12 months.
- B2B lead-gen: CAC appears stable, but sales-cycle slippage reduces realized ROAS and requires tighter qualification.
When to Use CAC and Common Misunderstandings
- Use CAC when deciding budget pacing, channel mix, and offer strategy at weekly or monthly cadence.
- Do not compare CAC across periods with different attribution windows without adjustment.
- Do not treat CAC as complete profitability; always pair with contribution margin and LTV quality.
Methodology and Calculation Logic
This calculator uses a direct unit-economics formula: total paid spend divided by new customers in the same measurement window. For consistent interpretation, keep spend, conversions, and attribution settings aligned to one period and one channel scope.
Accuracy Verified
Last reviewed on February 20, 2026 against industry data, platform changes, and user feedback. This calculator's formulas and benchmarks remain current.
CAC Calculator Module
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