Click-to-Open Rate Calculator (CTOR)

Formula CTOR = (Clicks ÷ Opens) × 100
CTOR (%)

Related Calculators

CTOR = (Clicks ÷ Opens) × 100

Use this free, online CTOR calculator to calculate your click-to-open rate instantly. Enter any two known values (clicks, opens, or rate) and it solves for the third, no sign-up required.

What Is Click-to-Open Rate (CTOR)?

Click-to-open rate (CTOR) measures what percentage of people who opened an email then clicked a link inside it. Unlike email CTR, which is measured against everyone the email was delivered to, CTOR isolates content and call-to-action performance specifically among people who actually saw the email, it answers “given that someone opened this, how compelling was what was inside?”

The Apple MPP Paradox: Why CTOR Can Be Understated, Not Overstated

This is the part almost nobody explains correctly, and it’s the opposite of what most marketers assume.

You’ve probably heard that Apple Mail Privacy Protection (MPP) “inflates” email metrics. That’s true for open rate. But CTOR’s formula is clicks divided by opens, and opens is the denominator. So when MPP artificially inflates the number of opens, it makes the CTOR fraction smaller, not larger. If Apple registers 1,000 “opens” when only 600 people actually looked at your email, your CTOR gets diluted by the 400 phantom opens sitting in the denominator, understating how engaging your content actually was.

What this means practically:

  • A CTOR that looks like it’s declining over time may not reflect worse content. It may simply reflect a growing share of your list using Apple Mail with MPP enabled
  • If your email service provider offers an “MPP exclusion” or “engaged opens” filter, turn it on before calculating CTOR. This removes the phantom opens from the denominator and gives a truer number
  • Compare your own CTOR over time on a consistent measurement method, rather than against a raw industry benchmark that mixes clean and MPP-polluted data

One more wrinkle worth knowing: clicks aren’t perfectly clean either. Enterprise security software (Microsoft Defender, Proofpoint, Mimecast, and similar tools) automatically pre-clicks links in incoming emails to scan for malware before a human ever opens the message. This can inflate raw B2B click data by an estimated 10% to 80%. Always use unique clicks (not total clicks) when calculating CTOR, and treat B2B numbers with extra skepticism if your provider doesn’t filter bot clicks.

How to Calculate Click-to-Open Rate

To calculate CTOR, divide clicks by opens, then multiply by 100.

CTOR = (Clicks ÷ Opens) × 100

Step by Step

  • Find your total unique clicks for the campaign you’re measuring
  • Find your total unique opens for the same campaign
  • Divide clicks by opens
  • Multiply by 100 to get a percentage

Worked Examples

  • Small campaign: 40 clicks, 250 opens 40 ÷ 250 × 100 = 16% CTOR
  • Mid-size campaign: 320 clicks, 3,800 opens 320 ÷ 3,800 × 100 = 8.42% CTOR
  • Agency-scale account: 3,200 clicks, 42,000 opens 3,200 ÷ 42,000 × 100 = 7.62% CTOR

Click-to-Open Rate Calculator Formula (Reverse Calculation)

Because this is a reverse-capable calculator, you can also start from a target CTOR and solve for clicks or opens instead.

  • To find Clicks: Clicks = (CTOR ÷ 100) × Opens
  • To find Opens: Opens = Clicks ÷ (CTOR ÷ 100)

What Is a Good CTOR?

Current 2026 reports show CTOR climbing year over year, alongside a wide industry spread.

Context

Typical CTOR

Source

All-industry average (3.6M campaigns)

6.81%

MailerLite (2026), up from 5.63% in 2024

Industry range

2.96% – 14.82%

MailerLite (2026)

Manufacturing (highest)

~14.82%

MailerLite (2026)

Legal (2nd highest)

~14.72%

MailerLite (2026)

Media

~12.92%

MailerLite (2026)

Politics (lowest)

~2.96%

MailerLite (2026)

Insurance

~3.19%

MailerLite (2026)

Commonly cited “healthy” benchmark

10% – 15%

GetResponse, MarketAmp (2026)

Cited as “excellent”

20%+

Monday.com / GetResponse framework (2026)

Why the range is wide: industry engagement culture explains much of this, legal and manufacturing audiences tend to open fewer, more targeted emails and act on them deliberately, while high-volume consumer categories like politics see huge list sizes with much lower per-email intent. Remember the Apple MPP paradox above before reading too much into a single number: your CTOR may be more understated than an industry benchmark if your list skews heavily toward Apple Mail users.

How to Improve Your CTOR

  • Make sure the email body actually delivers on the promise made in the subject line, a mismatch here is the most common cause of low CTOR
  • Lead with the main offer or message near the top, rather than making readers scroll to find the point
  • Use a single, visually clear call-to-action rather than splitting attention across several competing links
  • Personalize content based on subscriber behavior or segment, not just their name
  • Turn on your ESP’s MPP exclusion or “engaged opens” filter if available, so your CTOR reflects real engagement rather than phantom Apple-inflated opens
  • A/B test email body layout and CTA placement. CTOR responds directly to content structure, unlike raw open rate

Frequently Asked Questions

The current all-industry average is 6.81% (MailerLite, 3.6 million campaigns), though a commonly cited “healthy” range is 10% to 15%, with 20%+ considered excellent. Industry varies enormously, from around 3% in politics and insurance to nearly 15% in manufacturing and legal.

Divide your unique clicks by your unique opens, then multiply by 100. For example, 40 clicks from 250 opens gives a 16% CTOR. The calculator above does this instantly, or you can use it in reverse to solve for clicks or opens.

It deflates it, which surprises most people. MPP inflates the opens count (the denominator), which makes the clicks-to-opens ratio smaller than it would be with only genuine opens. This is the opposite effect from open rate, which MPP inflates directly.

Open rate can’t distinguish a genuine open from an Apple Mail Privacy Protection pixel pre-load. CTOR, based on an actual click, requires real engagement, making it a more trustworthy signal of whether your content resonates with people who saw it, even though its own number is now somewhat understated by the same MPP effect.

Not completely. Enterprise security tools like Microsoft Defender and Proofpoint automatically pre-click links to scan for malware before a human sees the email, which can inflate raw B2B click data by 10% to 80%. Always use unique clicks rather than total clicks, and check whether your email platform filters bot clicks.

Use the reverse mode above: set “I want to calculate” to Opens, enter 20 for CTOR and 40 for Clicks. The calculator shows you need 200 opens.