Email Marketing ROI Calculator for Klaviyo
Klaviyo credits email with orders placed within its attribution window, by default 5 days after an open or a click, whether or not the email caused the order. This calculator turns that attributed revenue into the share email actually caused, applies your gross margin, and sets the result against everything email costs you. The maths runs in your browser.
Inputs
ROI breakdown
Incremental revenue
$0
Revenue email caused, at your incremental factor
Incremental gross profit
$0
Incremental revenue × gross margin
Total cost
$0
Klaviyo + agency or team
Net contribution
$0
Gross profit minus total cost
ROI on profit
0%
0× revenue per $1 of cost
Payback period
0 months
Months of incremental gross profit to cover a year's cost
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How the calculator works
Five steps, in the order the outputs appear:
- Incremental revenue = attributed revenue × incremental factor. This strips out orders that would have happened without the email.
- Incremental gross profit = incremental revenue × gross margin. Email costs are paid out of profit, not revenue, so this is the figure the costs are weighed against.
- Total cost = platform cost + agency or team cost, both annual.
- Net contribution = incremental gross profit − total cost. ROI on profit is that net figure divided by total cost. Revenue per $1 of cost is shown underneath, because it is the number most people quote.
- Payback period = total cost ÷ monthly incremental gross profit: how many months of email profit it takes to cover a year of spend.
Why attributed revenue needs discounting: Klaviyo uses last-touch attribution with a 5-day window for email opens and a 5-day window for email clicks by default (Klaviyo Help Center, checked October 2026). An order placed four days after someone opened a newsletter is credited to that newsletter, whether or not they read it. Apple Mail Privacy Protection opens make it worse. We explain the settings we change in email revenue attribution in Klaviyo, and the rules we hold our own case studies to.
The assumptions, and how to replace them
- The incremental presets are assumptions, not industry facts. 40%, 55% and 70% give you a cautious, middle and flow-heavy view. Flows such as abandoned cart and welcome reach people at a decision point, so more of their revenue tends to be caused by the email; campaigns to frequent buyers tend to be credited with orders those buyers were placing anyway. Your mix decides where you sit.
- Only a holdout test measures your factor. Hold a random share of the list back from email for 30 to 60 days and compare revenue per person. Then put that number in place of the preset.
- Margin matters more than people expect. At a 60% gross margin, $100,000 of incremental revenue is $60,000 to pay costs from. At 30%, it is $30,000. The same email program can look excellent for one brand and marginal for another.
- Costs are annual and complete. Include internal time. A program that looks cheap because the founder writes every email at night is not cheap.
- It is a one-year view. It ignores the lifetime value of customers email brings back, which is real but harder to measure. Our customer lifetime value calculator covers that side.
Email marketing ROI questions
How do you calculate email marketing ROI?
Take the revenue email actually caused (attributed revenue multiplied by the incremental share), multiply it by your gross margin to get gross profit, then subtract everything email costs you. Divide that net figure by the cost to get the return on each dollar spent. This calculator does exactly that, and shows revenue per dollar of cost alongside it.
Why not use the revenue Klaviyo reports?
Because Klaviyo reports attributed revenue, not caused revenue. By default it credits an order to the last email a customer opened or clicked in the previous 5 days, so a customer who would have bought anyway still counts. Attributed revenue is a useful signal for comparing flows and campaigns. It overstates what email earned for the business.
What incremental factor should I use?
Your own, once you have measured it. Until then the presets are planning assumptions: 40% if most of your email revenue comes from campaigns to people who already buy often, 55% as a middle case, 70% if most of it comes from flows such as abandoned cart and welcome that reach people at a decision point. None of these is an industry figure. A holdout test replaces the guess with your number.
How do I run a holdout test?
Pick a random share of your list, often 10-20%, and send it nothing from email for 30 to 60 days. Keep everything else the same. Compare revenue per person between the group that got email and the group that did not. The difference, scaled to the whole list, is the revenue email caused. Run it outside major sales, or the result will swing on one promotion.
What costs should I include?
Everything it takes to run email and SMS: the Klaviyo plan and SMS credits, any agency or retainer, the time of anyone in-house who plans, writes, designs or reports on email, and paid apps that exist only to feed email, such as a pop-up or reviews tool. Leaving out internal time is the most common way ROI gets flattered.
Should the calculation include SMS?
Match the two sides. If the attributed revenue you enter includes SMS, include the SMS plan and credits in the cost. If you want email on its own, take SMS revenue and SMS costs out of both.
What is a good email marketing ROI?
Any return where incremental gross profit covers the full cost, with room to spare. Published ROI figures for email are usually attributed revenue divided by platform cost, which is the most flattering version of the sum and rarely includes people or margin. Compare your result with your own past results and with your other channels on the same basis.
Numbers look thin? The usual causes are flows that are missing or misfiring, campaigns sent to the whole list, and deliverability. Our free Klaviyo audit checks all three and sends a written plan within 24 hours, or see how we run accounts as a Klaviyo agency.