The Ecommerce ROI Formula
The standard ROI formula is simple, but ecommerce requires you to define "investment" carefully:
ROI = ((Net Profit − Total Investment) ÷ Total Investment) × 100
For ecommerce, Total Investment includes: product cost (COGS), advertising spend, platform fees (Shopify, Amazon), shipping costs, returns/refunds, and payment processing fees. Missing any of these inflates your ROI figure.
Real Ecommerce ROI Examples
Facebook Ads Campaign
You spend $2,000 on Facebook ads. The ads generate $7,500 in revenue. Product cost for those orders is $3,000. Shipping: $400. Platform fees: $225.
Total Investment: $2,000 (ads) + $3,000 (COGS) + $400 (shipping) + $225 (fees) = $5,625
Net Profit: $7,500 − $5,625 = $1,875
ROI = ($1,875 ÷ $5,625) × 100 = 33.3%
Solid. Every $1 invested returns $1.33 in profit.
Amazon FBA Product Launch
You invest $8,000 in inventory. Amazon fees (FBA + referral): $2,400. PPC ads: $1,200. Revenue in 90 days: $18,000.
Total Investment: $8,000 + $2,400 + $1,200 = $11,600
Net Profit: $18,000 − $11,600 = $6,400
ROI = ($6,400 ÷ $11,600) × 100 = 55.2%
Strong for a product launch. Aim to improve with better PPC targeting.
Key Ecommerce ROI Metrics to Track
ROAS (Return on Ad Spend)
Revenue ÷ Ad Spend
4x+ is generally profitable
Customer Acquisition Cost
Total Marketing Spend ÷ New Customers
Should be < 30% of LTV
Customer Lifetime Value
Avg Order × Purchase Frequency × Lifespan
Higher LTV = more ad budget headroom
Inventory ROI
(Revenue − COGS) ÷ COGS × 100
Target 50%+ for healthy margins
Frequently Asked Questions
What is a good ROI for ecommerce?
A 20–50% ROI is considered healthy for most ecommerce businesses. Amazon FBA sellers often target 30%+ on inventory. Ad campaigns should aim for at least 3–4x ROAS to be profitable after fees.
Should I include my time in ROI calculations?
Yes, if you're running the business yourself. Assign an hourly rate to your time and include it as a cost. Otherwise you're subsidizing the business with unpaid labor.
How is ecommerce ROI different from ROAS?
ROAS only measures ad spend vs revenue. ROI is broader — it includes all costs (inventory, fees, shipping, returns). A campaign can have 5x ROAS but negative ROI if product costs are high.
How often should I calculate ecommerce ROI?
Monthly for overall business ROI. Weekly or daily for ad campaigns. Real-time tracking via your ad platform dashboard helps catch underperforming campaigns early.
What kills ecommerce ROI most?
High return rates, rising ad costs (CPM), and untracked fees. Amazon sellers often underestimate FBA fees. Shopify sellers miss payment processing (2.9% + $0.30 per transaction).