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Email CTOR Calculator

Calculate click-to-open rate to measure how many recorded email openers also clicked a tracked link, then compare an optional target.

Unique Opens, Unique Clicks and Target CTOR

Use figures from the same email campaign, audience scope and reporting period so the numerator and denominator describe the same activity.

Unique recipients recorded as opening the selected email.
Unique recipients who clicked at least one tracked link.
Your own planning or historical click-to-open target.
Click-to-Open Rate (CTOR)-
Unique Openers Without a Click-
Clicks per 100 Unique Opens-
Unique Clicks at Target CTOR-
Click Gap vs Target-
Target Comparison-

Example: 14.06% Click-to-Open Rate

Unique opens: 3,200

Unique clicks: 450

CTOR: 14.06%

Openers without a click: 2,750

Target CTOR: 16.00%

Target unique clicks: 512

Gap to target: 62 clicks

The sample inputs shown here match the default calculator values so the example can be reproduced directly.

Formula

CTOR = Unique Clicks / Unique Opens x 100Openers Without a Click = Unique Opens - Unique ClicksTarget Clicks = Unique Opens x Target CTOR

Input Checklist

Same scope: Keep delivery, engagement, conversion and cost figures from one comparable campaign or reporting window.Unique metrics: Use unique recipient counts where the calculator requests unique opens, clicks or unsubscribes.Decision context: Read email metrics together instead of optimizing one rate in isolation.

Reporting Note

Email platforms can count deliveries, opens, clicks, bounces, conversions and unsubscribes differently. When comparing campaigns, keep the provider, attribution window, recipient scope and unique-versus-total counting method consistent so a change in measurement is not mistaken for a change in performance.

Add This Email CTOR Calculator to Your Website

Embed this free calculator on an email marketing, analytics or campaign-planning resource page. The ?embed=1 view keeps the calculator focused and supports responsive iframe resizing.

Embedding requirement: Keep the SolveIndex attribution and source link visible and unchanged.
How to Interpret the Result
CTOR focuses on engagement after an email is recorded as opened. It can help compare content and call-to-action effectiveness, but open-tracking limitations also flow into the denominator. Treat the optional target as your own planning reference rather than a universal benchmark, and read CTOR with CTR, open rate and conversion metrics.
Marketing - Email Marketing
Use the metric in context
Learn the metric definition, formula, reporting scope, common mistakes and how it connects with the rest of the email funnel.
Read the Email CTOR GuideBrowse all guides
Email CTOR Calculator Frequently Asked Questions
CTOR means click-to-open rate. It measures the percentage of unique openers who also clicked a tracked link.
Divide unique clicks by unique opens and multiply by 100.
CTR divides unique clicks by delivered emails, while CTOR divides unique clicks by unique opens.
With consistent unique-recipient definitions it should not. If your report shows otherwise, check whether clicks and opens use different scopes or counting rules.
No. They answer different questions. CTR measures engagement across delivered recipients; CTOR focuses on recorded openers.
Move between engagement, deliverability, conversion and financial-return metrics without mixing their definitions.
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Email CTOR Calculator Disclaimer: Results are planning and reporting calculations based on the inputs you provide. Email platforms can use different tracking, attribution and counting rules, so compare figures only when definitions and reporting windows are consistent.