- Email ROI formula: (Email revenue − Email cost) ÷ Email cost × 100. “Revenue ÷ cost” is a return multiple, not ROI. Mixing them up is the most common mistake.
- So “$36 for every $1” is a 36:1 return, which is a 3,500% ROI by the standard formula, not 3,600%.
- Budget on profit ROI: (Email revenue × Gross margin − Discounts − Email cost) ÷ Email cost × 100. Then check it with a holdout test.
- Klaviyo credits orders within 5 days of an email click or open by default. Opens can be inflated by Apple Mail, so attributed revenue is an upper estimate.
- In Litmus’s 2026 survey, 37% of marketers reported 20:1–36:1 and 13% weren’t sure. Run yours in the email ROI calculator.
Search for the email ROI formula and you’ll find two different formulas, both called ROI, giving two different answers. Then a famous stat on top that most Shopify stores can’t compare themselves to anyway.
That’s how you end up with a deck saying email returns 40x while the bank account says something else.
So let’s fix it. The correct formula, the three versions worth knowing, the costs people leave out, and the Klaviyo settings that quietly inflate the number. Tricks first.
Email Marketing ROI CalculatorEnter list size, sends, click rate, conversion rate, AOV and costs and see what your email program returns per $1.Run my numbers →The email ROI formula (and the one that isn’t ROI)
That’s standard ROI: what you earned on top of what you spent. Now the other one you’ll see, for example in Shopify’s email metrics guide:
Both are useful. They are not the same thing. Shopify’s guide cites HubSpot data for $36 for every $1 spent and calls it a 3,600% ROI. By the standard formula, $36 back on $1 is ($36 − $1) ÷ $1 = 3,500%. Small gap at 36x, a big one at 3x: a 3:1 return is 200% ROI, not 300%.
My rule: say “return multiple” when you divide, and “ROI” only when you subtract cost first.
3 tricks before you trust any email ROI number
1. Write down the cost stack
Most inflated ROI numbers only count the platform bill. Here’s the full stack:
| Cost | Often forgotten? |
|---|---|
| Email platform subscription (e.g. Klaviyo) | Rarely |
| Apps and tools (reviews, design, popups, data) | Often |
| People: in-house time, freelancer or agency | Very often |
| Sign-up incentives (welcome codes, giveaways) | Very often |
| Discounts redeemed through email | Almost always |
| Product cost (gross margin) | Ignored by revenue ROI |
2. Know your attribution window
Klaviyo’s attribution help article says new accounts use last-touch attribution with default windows of 5 days for email clicks and 5 days for email opens. Since Apple Mail Privacy Protection, opens are partly machine-generated (my CTOR benchmark post explains why), so open-based credit is generous.
Shopify Messaging, per Shopify’s guide, uses last-direct-click. Different tools, different revenue for the same emails. Pick one source and one window, and keep them fixed.
3. Split flows from campaigns
Klaviyo’s RPR benchmarks show automated flows averaging $1.94 revenue per recipient vs $0.11 for email campaigns. One blended ROI hides which half is doing the work.
Version 1: revenue ROI (the email ROI formula most stores use)
A Shopify store’s Klaviyo account shows $20,000 email-attributed revenue last month. Costs: $400 platform, $100 apps, $1,500 for the freelancer who writes and builds emails. Total cost $2,000.
- Return multiple: $20,000 ÷ $2,000 = 10:1.
- Revenue ROI: ($20,000 − $2,000) ÷ $2,000 × 100 = 900%.
Looks great. But $20,000 of revenue isn’t $20,000 of profit.
Version 2: profit ROI (use this one to budget)
- Gross margin is 60%, so gross profit on email orders = $20,000 × 60% = $12,000.
- Email discount codes and welcome incentives redeemed: $2,500.
- Profit ROI: ($12,000 − $2,500 − $2,000) ÷ $2,000 × 100 = 375%.
Still a strong channel. But 375% is the number to plan with, not 900%. Get your margin from the profit margin calculator.
If you only remember one thing: a discount-heavy campaign can show a fat revenue ROI and lose money once margin and the discount come out.
Version 3: incremental ROI (the honest one)
Attributed revenue includes people who would have bought anyway. To see what email really added, hold out a random slice of the list from campaigns for a few weeks and compare revenue per person.
- A one-month test. Emailed group: 40,000 people, $0.50 revenue per person.
- Held-out group: $0.30 per person, from people who weren’t emailed at all.
- Incremental revenue: ($0.50 − $0.30) × 40,000 = $8,000.
- Incremental profit ROI for that month, with $1,000 of email discounts redeemed: ($8,000 × 60% − $1,000 − $2,000 cost) ÷ $2,000 × 100 = 90%.
Still positive, so email pays. But it’s a very different conversation from 900%.
Keep holdouts small (5–10% of the list) and short, so you don’t give up much revenue to learn the answer. Run campaigns and flows tests separately.
What is a good email ROI? The data that exists
There’s no verified Shopify-only benchmark. The best recent data is Litmus’s State of Email 2026 survey of 502 marketers in the US, UK, Australia and New Zealand, reported by MediaPost:
| Reported email return (Litmus 2026) | Share of marketers |
|---|---|
| 1:1 to 10:1 | 3% |
| 10:1 to 20:1 | 13% |
| 20:1 to 36:1 | 37% |
| 36:1 to 45:1 | 25% |
| More than 45:1 | 8% |
| Unsure | 13% |
Litmus’s older industry figures put retail, ecommerce and consumer goods at 45:1, but that came from its 2020 survey. Two caveats: these are self-reported, and they’re revenue multiples, not profit ROI. Use them as a sanity check, not a target.
How to calculate your email ROI on Shopify (15 minutes)
- Pick last full month. In Klaviyo, note email-attributed revenue, split into flows and campaigns.
- Write down your attribution windows so next month uses the same ones.
- Add up every cost from the stack table above, including people time.
- Pull discount totals for email-only codes from Shopify.
- Work out the return multiple, revenue ROI and profit ROI.
- Plan a small holdout test to get incremental ROI next quarter.
The email ROI calculator handles steps 3–5 in seconds, and the email revenue calculator shows how much more email could bring in. For the share of total sales email should drive, see what percentage of revenue should come from email.
6 ways to raise email ROI without sending more
1. Build the flows first
Flows earn per recipient many times what campaigns do, every day, with no extra cost. Start with the abandoned cart flow and a welcome series. My welcome flow revenue per recipient guide shows how to benchmark it.
2. Cut the cost line you control
Klaviyo bills on active profiles, so emailing people who never open costs money and earns nothing. See how to lower your Klaviyo bill and model plans in the Klaviyo pricing calculator.
3. Stop leading with discounts
Every code comes straight off profit ROI. Test free shipping thresholds or bundles instead. My AOV with email post has the playbook.
4. Segment campaigns
Send launches to buyers of related products, not the whole list. Fewer sends, higher RPR, lower complaint risk.
5. Fix deliverability
Emails in spam earn nothing. Check the basics against the Gmail and Yahoo sender requirements.
6. Compare channels on the same formula
If you run texts too, use the same three versions in my SMS marketing ROI formula post, so email and SMS are compared fairly. For paid ads, the matching number is your break-even ROAS.
A simple email ROI scorecard
- Return multiple for the headline, labelled as revenue ÷ cost.
- Profit ROI for budgeting, with margin and discounts taken out.
- Incremental ROI once a quarter, from a holdout.
- Flows vs campaigns reported separately.
- Same window, same source every month.
Want Inboxoo to set this up for you?
We build and run Klaviyo email & SMS retention for Shopify brands and get paid on results.
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FAQ
What is the formula for email marketing ROI?
Email ROI equals email revenue minus email cost, divided by email cost, times 100. If email earned $10,000 and cost $1,000, ROI is 900%. Dividing revenue by cost without subtracting gives a return multiple (10:1), which is a different number.
What costs should I include in email ROI on Shopify?
Your email platform bill, any email apps or design tools, the time of whoever writes, designs and builds emails (in-house, freelancer or agency), the cost of sign-up incentives, and discounts redeemed through email. For profit ROI, also take out product cost using your gross margin.
What is a good email ROI for ecommerce?
There is no single verified benchmark for Shopify stores. In Litmus’s State of Email 2026 survey of 502 marketers, 37% reported a return of 20:1 to 36:1, 25% reported 36:1 to 45:1, 8% reported more than 45:1 and 13% were unsure. These are self-reported revenue ratios, not profit.
Does Klaviyo attribution inflate email ROI?
It can. By default Klaviyo uses last-touch attribution with 5-day windows for email clicks and opens, so an order placed within 5 days of an open is credited to email even if the customer would have bought anyway. A holdout test shows how much of that revenue email really added.
Is $36 for every $1 spent a real email ROI?
Shopify’s email metrics guide cites HubSpot data for $36 per $1 spent. It is an average return multiple across many businesses, not a Shopify-specific benchmark, and it is revenue-based. Work out your own number with your real costs and margin.
Should I calculate ROI for flows and campaigns separately?
Yes. Klaviyo’s published RPR benchmarks show automated flows averaging $1.94 per recipient against $0.11 for email campaigns. A blended ROI hides weak campaigns behind strong flows, or the other way round.
Want Inboxoo to set this up for you?
We build and run Klaviyo email & SMS retention for Shopify brands and get paid on results.
Chat on WhatsAppWant to know the exact quotation? Contact now
Keep reading
SMS marketing ROI formula
Revenue ROI vs profit ROI vs incremental ROI, the forgotten costs, and worked examples.
7 min read →BenchmarksWhat % of revenue should come from email?
The benchmark ranges, the attribution traps, and the six levers that move your email revenue share fastest.
7 min read →Klaviyo pricingHow to lower your Klaviyo bill
Klaviyo charges for active profiles, not list size. Suppress the dead weight the right way and pay for people who buy.
7 min read →- Shopify: Email marketing metrics, 13 KPIs to track (May 2025)
- Klaviyo Help Center: Understanding Klaviyo message attribution
- Klaviyo: What is revenue per recipient? (Dec 2024)
- MediaPost: Litmus State of Email 2026 report findings (Apr 2026)
- Litmus: The ROI of email marketing (Jul 2025)
Worked examples in this post use illustrative numbers, not client results. Benchmarks are linked to their original publisher.