Ad Math Utilities

Paid Ad ROI & CPI Calculator

Evaluate your campaign economics. Calculate your Cost Per Acquisition (CAC), Return on Ad Spend (ROAS), and identify the maximum Cost Per Click you can afford.

Campaign Inputs

Customer Lifetime Value (LTV)$45.00
$5$100$200+
Estimated Cost Per Click (CPC)$0.40
$0.05$1.50$3.00
Landing Page Conv. Rate10%
1%15%30%
Signup to Paid Conv. Rate4%
0.5%10%20%
Campaign Status: Unprofitable

Your ad spend is higher than the customer lifetime value. Try optimizing your landing page conversion rate or improving your ad CTR to get a lower CPC.

Return on ad spend
0.45xLTV / CAC Ratio
Acquisition Cost (CAC)
$100.00Ad spend per customer
Cost Per Registration
$4.00Cost per sign-up (CPI)
Net Profit Margin per Customer
$-55.00LTV - CAC

You are losing money on every user you acquire. Optimize conversions.

Break-Even CPC Bidding Limit
$0.18Max bid threshold

If your CPC exceeds this limit on TikTok or Meta, the campaign will instantly run at a loss.

How is this calculated?

Your CAC is determined by multiplying the number of ad clicks required to generate one paying customer (which is 1 / (Landing Page Conversion % * Signup to Paid Conversion %)) by your Cost Per Click (CPC). CPI is computed as CPC / Landing Page Conversion %. Optimizing your ad creative decreases the CPC bid rate, directly lowering your customer acquisition costs.

High-CTR Ad Creative

Lower your CAC with slideshow video ads

High-CTR video carousels convert up to 3× better than generic static templates. SlidesTok helps you turn screenshots, logos, and testimonials into high-engagement slideshows for TikTok and Reels ads, lowering CPC costs.