Email Marketing ROI Calculator

Enter your list size, how often you send, your open and click rates, and what a conversion is worth. The calculator works out your monthly revenue, profit, cost per conversion, and the minimum list size you need to cover your costs.

Explain like I'm 5 (what even is email marketing ROI?)

You have a list of people who said you could email them. You send them messages about things you sell. Some open the email, some click something in it, and a few of those actually buy. Email marketing ROI asks: are you making more money from those buyers than you're spending on the email platform and the content to fill it? If yes, by how much? If not, how many more subscribers do you need before you are?

Calculate

Enter your numbers, then press Calculate.

Prove it

Monthly emails sent = list size × campaigns per month. Monthly opens = emails sent × open rate. Monthly clicks = emails sent × click rate. Monthly conversions = clicks × conversion rate. Monthly revenue = conversions × revenue per conversion. Monthly cost = platform cost + content cost. ROI = (total net profit ÷ total cost) × 100. Cost per conversion = monthly cost ÷ monthly conversions. Break-even list size = monthly cost ÷ (campaigns per month × click rate × conversion rate × revenue per conversion).

Useful? Save this calculator: press Ctrl + D to bookmark it.

How to find accurate inputs

The result is only as good as the numbers you put in. Here is where to find each one.

List size

Use your active subscriber count, not your total list. Most email platforms let you filter by engagement status. A list of 10,000 with 3,000 unengaged subscribers sitting at the bottom is not a list of 10,000 for the purposes of this calculation. Use the number who are likely to see your emails.

Campaigns per month

How many separate emails do you send to your full list each month? Triggered sequences sent to segments count separately, but if you are not sure, start with your broadcast campaigns and add sequences later once you have a clear picture of those numbers.

Open rate

Pull this from your email platform's reporting. Bear in mind that open tracking has become less reliable since Apple Mail Privacy Protection launched in 2021,iOS devices now pre-load images, which inflates open rates for lists with a lot of iPhone users. Use it as a directional number, not a precise one. Industry averages sit around 20–25% for B2C and 15–20% for B2B, though these vary widely by sector and list quality.

Click rate

This is clicks as a percentage of total emails sent (not opens). Your platform may also show click-to-open rate (CTOR), which is clicks as a percentage of opens. This calculator uses click rate as a percentage of sends. If your platform only shows CTOR, multiply it by your open rate and divide by 100 to convert. Typical click rates sit between 1–5% for most lists.

Conversion rate

This is the percentage of people who clicked and then completed the goal: made a purchase, booked a call, signed up. If you have e-commerce tracking set up and UTM parameters on your email links, you can find this in Google Analytics by filtering sessions from your email channel and looking at the goal or purchase conversion rate. If not, estimate conservatively: 1–3% is realistic for most e-commerce; B2B lead generation is often lower.

Revenue per conversion

For e-commerce: use your average order value. For lead generation: use the average revenue a converted lead generates, either as a deal value or a lifetime value estimate. If your product has a range of prices, use a weighted average based on what email campaigns typically sell, not your overall product mix.

Platform and content costs

Your email platform cost is whatever you pay your ESP (Mailchimp, Klaviyo, ActiveCampaign, and the rest) each month. Content cost is anything you pay to write, design, or produce the emails: copywriter fees, designer time, or your own time costed at an hourly rate. If you write the emails yourself and are not costing your time, leave it at zero, but know the result will look more flattering than it really is.

What the break-even list size tells you

The break-even list size is the minimum number of engaged subscribers you need, at your current send frequency, click rate, conversion rate, and revenue per conversion, for your email channel to cover its own costs.

If your current list is above the break-even threshold, email is covering its costs and generating surplus revenue. If it is below, you are either investing ahead of your list growth (which is sometimes the right call), or your rates and revenue per conversion need attention before the list size matters much.

The most useful thing to do with this number is to work backwards: if break-even is 2,000 subscribers and your list is at 1,200, you need either 800 more subscribers at the same rates, or you need to improve your conversion rate or average order value so the break-even moves down to where you already are.

What this calculator does not account for

This is a steady-state model. It assumes every campaign performs at the rates you enter, every month, for the full period. Real email lists are messier: open rates decline over time as lists grow stale, seasonal campaigns outperform regular sends, and a single well-timed re-engagement campaign can change the numbers significantly.

It also does not account for:

  • Segmentation: a well-segmented list typically outperforms a single-segment blast; this calculator models the average across your full list
  • List growth: if your list is growing, your results improve over the period; this calculator holds list size constant
  • Deliverability: emails that land in spam or promotions tabs do not get opened; if deliverability is an issue, your effective open rate is lower than the one you are entering
  • Attribution: some of your email-driven revenue will get attributed to other channels in last-click models; the true contribution of email is often higher than analytics shows

For a broader view of marketing channel returns, try the SEO ROI Calculator or the general-purpose ROI Calculator.

Nothing on this page is financial or marketing advice. For decisions that matter, talk to someone who knows your specific situation.

Related calculators

Email ROI is one input. These fill in the rest of the picture.

Frequently asked questions

How do you calculate email marketing ROI?

Email marketing ROI = (total net profit ÷ total cost) × 100. Net profit is the revenue your email list generates minus your platform and content costs. Revenue is worked out by multiplying emails sent by your click rate, then your conversion rate, then revenue per conversion.

What is a good email marketing ROI?

Industry figures often cite £36 back for every £1 spent, but the range is huge depending on sector, list quality, and what you are selling. A better question is whether your ROI is improving month on month. Use this calculator to track your baseline, then measure whether changes to your copy, offer, or segmentation move the number.

What is the difference between open rate and click rate?

Open rate is the percentage of delivered emails that were opened. Click rate (click-through rate) is the percentage of emails sent that got at least one click. This calculator uses click rate as a percentage of sends. If your platform shows click-to-open rate (CTOR) instead, multiply it by your open rate and divide by 100 to convert.

What counts as a conversion?

Whatever the email is trying to get the reader to do: buy something, book a call, sign up for a trial. Use the average revenue that a single conversion generates. For e-commerce that is average order value; for lead generation it is average deal value or customer lifetime value.

What is break-even list size?

The minimum number of subscribers you need, at your current rates, for email revenue to cover your platform and content costs. If your list is below this number, the channel is not yet self-funding. You can close the gap by growing the list, improving click or conversion rates, or increasing revenue per conversion.

Last updated 29 April 2026 by Andrew Laws.