Free tool · Email marketing Email metrics calculator: open rate, click rate and ROI
Enter what your email platform reports for one send: sent, bounced, opens, clicks, unsubscribes and spam complaints. You get every rate on the same base, the complaint rate checked against the limits Gmail and Yahoo publish, and ROI if you add revenue and cost.
- Seven rates, one base
- Gmail / Yahoo spam limits
- Runs locally
Rates from one email send
Sent is required. Use unique opens and unique clicks (people, not events), as most email platforms show them. Revenue and cost are optional.
Messages handed to the email platform for this send.
Hard and soft bounces together. Delivered = sent − bounced.
Recipients who opened at least once.
Recipients who clicked at least one link.
Recipients who unsubscribed from this send.
Recipients who marked it as spam, as reported by your platform.
If your platform labels opens from Apple Mail Privacy Protection or other automatic loading, enter their share to see an adjusted open rate.
Orders or pipeline you attribute to this send, for example from UTM-tagged links.
Platform fees, design and copy time, list costs.
Click rate (CTR)
3.00%
Unique clicks ÷ delivered. Not affected by automatic opens.
Open rate
40.0%
Unique opens ÷ delivered. Includes opens recorded by privacy features, so treat it as an upper bound.
Share these inputs: the values go after the # in the link, so they never reach a server.
https://tapcub.com/tools/email-metrics-calculator
Version v1.0Updated Update history
Which numbers to trust
Since 2021 the open rate has measured something different from what it used to. Read the rates in this order.
Click rate
The cleanest engagement number: a click needs a person. 591 unique clicks from 19,700 delivered is 3.00%. Compare sends, subject lines and segments on this.
Open rate
Opens are counted when a tracking image loads. Apple says Mail Privacy Protection downloads remote content in the background by default, regardless of whether the email is read, so those recipients all look like openers. Use open rate for trends within the same list, not as proof of reading.
Click-to-open rate
Clicks ÷ opens says how well the content worked for openers. Inflated opens push CTOR down, so a drop can mean more automatic opens, not worse content.
Complaint and unsubscribe rate
Unsubscribes are a healthy exit. Complaints hurt delivery for everyone on your domain. Gmail's and Yahoo's published limits are below; keep well under them.
No industry averages here. Open and click rates depend on list source, frequency, audience and how each platform counts, so published averages rarely match your setup. Compare your own sends with each other.
Three steps
Take the numbers from your email platform's report for one send or one period.
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1
Enter sent and bounced
Delivered is worked out for you. Every other rate uses delivered as the base.
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2
Enter unique opens, clicks, unsubscribes and complaints
Use unique counts. If your platform separates machine or Apple privacy opens, enter their share for an adjusted open rate.
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3
Add revenue and cost
Revenue you attribute to the send (tagged links make this possible) and what the send cost give revenue per email and ROI.
Every rate on delivered emails
Delivered = sent − bounced. Open, click, unsubscribe and complaint rates divide by delivered, because a bounced email never had a chance. Click-to-open divides by opens.
- Delivery rate = (sent − bounced) ÷ sent; bounce rate = bounced ÷ sent
- Open rate = unique opens ÷ delivered; click rate = unique clicks ÷ delivered
- Click-to-open rate = unique clicks ÷ unique opens = click rate ÷ open rate
- Complaint rate = spam complaints ÷ delivered. Gmail's Postmaster Tools spam rate uses mail delivered to engaged recipients' inboxes as the base, so it will not match your platform's figure exactly
- Email ROI = (revenue − cost) ÷ cost
| Mailbox provider | What they publish | Source |
|---|---|---|
| Gmail | Keep the Postmaster Tools spam rate below 0.10% and avoid ever reaching 0.30%. All senders must stay below 0.3% | Email sender guidelines |
| Gmail, more than 5,000 messages a day to Gmail accounts | SPF, DKIM and DMARC; one-click unsubscribe on marketing and subscribed messages | Email sender guidelines |
| Yahoo | Keep your spam rate below 0.3%; bulk senders honor unsubscribes within 2 days | Sender best practices |
One newsletter, worked by hand
A software company sends its monthly newsletter to 20,000 subscribers. These are the numbers the calculator starts with.
| Metric | Calculation | Result |
|---|---|---|
| Delivered | 20,000 − 300 | 19,700 (98.5%) |
| Open rate | 7,880 ÷ 19,700 | 40.0% |
| Click rate | 591 ÷ 19,700 | 3.00% |
| Click-to-open rate | 591 ÷ 7,880 | 7.5% |
| Unsubscribe rate | 39 ÷ 19,700 | 0.20% |
| Complaint rate | 12 ÷ 19,700 | 0.06% |
| Revenue per delivered email | $9,850 ÷ 19,700 | $0.50 |
| ROI | ($9,850 − $1,200) ÷ $1,200 | 720.8% |
If the platform reports that half of the 7,880 opens came from Apple privacy loading, the adjusted open rate is 3,940 ÷ 19,700 = 20.0%. Click rate stays at 3.00%. Sample figures.
Where email metrics go wrong
Most disagreements about email performance come from different denominators.
Treating opens as reads
Privacy features load images without a person reading. A rising open rate after 2021 may be Apple Mail, not better subject lines.
Mixing bases
Click rate on sent and open rate on delivered cannot be compared. Use delivered for every rate except click-to-open.
Total instead of unique
One person clicking five links is five total clicks and one unique click. Rates use unique counts.
Ignoring complaints
A send can have a great click rate and still damage delivery for the next ten. Check the complaint rate on every send.
What happens after the click
TapCub does not count email opens. It counts what recipients do once they land on your site or app: sessions, conversions and revenue from each email link, so ROI uses outcomes you measured yourself.
Email as a channel
Visits tagged utm_medium=email, newsletter or edm are grouped into an Email channel next to search and social.
Learn moreLink-level results
utm_content tells the header button from the footer link: sessions, conversions and rate per link in one campaign.
Learn moreFirst and last touch
See whether a newsletter introduces customers that another channel closes later.
Learn moreEmail metrics questions
Still have a question?
Chat with the team behind TapCub — we usually reply within a few hours on business days.
How do you calculate email open rate?
Unique opens divided by delivered emails (sent minus bounced). 7,880 opens from 19,700 delivered is 40.0%. Some platforms divide by sent instead; say which base you use when you compare.
What is the difference between click rate and click-to-open rate?
Click rate divides unique clicks by delivered emails and measures the whole send. Click-to-open rate divides clicks by opens and measures the content for people who opened. 591 clicks, 19,700 delivered and 7,880 opens give 3.00% and 7.5%.
Why is my open rate so high?
Probably automatic opens. Apple Mail Privacy Protection loads remote content in the background whether or not the email is read, and some security scanners load images too. If your platform labels these opens, enter their share for an adjusted rate, and judge sends by clicks.
What spam complaint rate is too high?
Gmail asks senders to keep the Postmaster Tools spam rate below 0.10% and never reach 0.30%; Yahoo asks for below 0.3%. Postmaster Tools uses its own base (mail delivered to engaged recipients' inboxes), so treat your platform's complaint rate as an approximation and stay well under 0.1%.
How do you calculate email marketing ROI?
(Revenue attributed to the email − cost of the email) ÷ cost. $9,850 revenue on a $1,200 send is 720.8%. Attribute revenue with tagged links and conversions measured on your site; the email platform's own revenue figure often counts any purchase after an open.
What is a good email open rate or click rate?
Your own previous sends to the same list are the useful reference. Published averages mix industries and list types and are distorted by automatic opens, so this page does not quote one.
Is delivery rate the same as inbox placement?
No. Delivered means the receiving server accepted the message; it may still go to the spam folder. Inbox placement needs seed tests or the mailbox provider's own tools.
Update history
New features, fixes and data refreshes for this tool, newest first.
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· v1.0
LaunchedFirst release.
Data this tool relies on
- Mailbox provider sender guidelines — checked 2026-11-10, reviewed every 12 months (next review by 2027-11-10)
Missing something or found an error? Tell us — requests that come up often go into the next update. All tool updates
Measure email by what it brings in
Tag your email links with UTM and TapCub shows sessions, conversions and revenue per send and per link, next to every other channel.