Return on Ad Spend (ROAS) = Revenue ÷ Ad Spend. A ROAS of 4 means you earned $4 for every $1 spent. Most e-commerce businesses target a ROAS of 3–5×, though profitable breakeven depends on your margin.

Cost Per Acquisition (CPA) = Ad Spend ÷ Conversions. It tells you how much each sale, lead, or sign-up costs. A lower CPA relative to your average order value means a more efficient campaign.

Cost Per Mille (CPM) = (Ad Spend ÷ Impressions) × 1,000. It represents the cost to show your ad 1,000 times. CPM is useful for comparing brand-awareness campaigns across platforms.

How is ROI different from ROAS?

ROI accounts for profit, not just revenue: ROI = (Revenue − Ad Spend) ÷ Ad Spend × 100. ROAS ignores cost of goods, so ROI gives a clearer picture of actual profitability.

What ROAS should I target?

It depends on your gross margin. If your margin is 40%, you need at least a 2.5× ROAS to break even on ad spend alone (1 ÷ 0.40). Higher margins allow lower breakeven ROAS.

Ad Spend Calculator

Name: Ad Spend Calculator
Availability: InStock
Author: Nham Vu

Enter your campaign budget, revenue, conversions, and impressions to instantly calculate ROAS, CPA, and CPM.

Campaign Inputs

Total Ad Spend ($) *

Revenue from Campaign ($) *

Conversions *

Impressions (optional, for CPM)

ROAS Return on Ad Spend

—

Revenue ÷ Ad Spend

ROI Return on Investment

—

(Revenue − Spend) ÷ Spend × 100

CPA Cost Per Acquisition

—

Ad Spend ÷ Conversions

CPM Cost Per 1,000 Impressions

—

(Spend ÷ Impressions) × 1,000

Summary

Enter your campaign budget, revenue, conversions, and impressions to instantly calculate ROAS, CPA, and CPM.

How it works

Enter your total ad spend (budget) for the campaign period.
Enter the total revenue generated from the campaign.
Enter the number of conversions (sales, leads, or sign-ups).
Enter total impressions if you want CPM calculated.
The calculator instantly shows ROAS, CPA, CPM, and ROI.

Use cases

Compare ROAS across Google Ads, Meta Ads, and TikTok campaigns.
Determine whether a campaign is profitable before scaling spend.
Calculate cost per acquisition to set realistic bidding targets.
Report CPM benchmarks to stakeholders for media planning.
Quickly sanity-check campaign numbers from an ad platform dashboard.
Plan budget allocation by reverse-engineering a target ROAS.

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu