SolveIndex
Explore22 freecalculators
Guides

Email Open Rate Calculator

Calculate unique email open rate from delivered emails, compare an optional target, and quantify unopened recipients and the open-volume gap.

Delivered Emails, Unique Opens and Target Rate

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

Emails successfully delivered to recipients in the selected campaign or period.
Unique recipients recorded as opening the delivered email.
Your own planning or historical comparison rate.
Email Open Rate-
Delivered Emails Not Opened-
Unique Opens per 1,000 Delivered-
Unique Opens at Target Rate-
Open Gap vs Target-
Target Comparison-

Example: 32% Email Open Rate

Delivered emails: 10,000

Unique opens: 3,200

Email open rate: 32.00%

Not opened: 6,800

Target open rate: 35.00%

Target unique opens: 3,500

Gap to target: 300 opens

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

Formula

Email Open Rate = Unique Opens / Delivered Emails x 100Unopened Delivered Emails = Delivered Emails - Unique OpensTarget Opens = Delivered Emails x Target Open Rate

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 Open Rate 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
Open rate is a recorded engagement signal, not a perfect observation of human reading. Compare campaigns using the same provider definition, delivered-email denominator and audience type, and interpret large changes alongside CTR, CTOR and conversion rate because privacy features and image-loading behavior can affect recorded opens.
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 Open Rate GuideBrowse all guides
Email Open Rate Calculator Frequently Asked Questions
Divide unique recorded opens by successfully delivered emails and multiply by 100. The calculator uses delivered emails so known bounces are excluded from the denominator.
Use delivered emails for this recipient-level rate. Sent volume includes delivery attempts that bounced, so dividing by sent emails mixes deliverability with open engagement.
Yes. Open tracking depends on remote-content or tracking-pixel behavior, so privacy features, image loading, caching and email-client settings can make recorded opens differ from actual human reading.
There is no universal threshold. Compare with your own historical campaigns and relevant peer benchmarks. Current 2026 ecommerce benchmarks vary by campaign type and industry, so use them as context rather than a hard grade.
Open rate shows recorded inbox engagement; CTR shows whether recipients clicked a tracked link. CTR, CTOR, conversion rate and ROI provide stronger downstream evidence of campaign performance.
Move between engagement, deliverability, conversion and financial-return metrics without mixing their definitions.
Email CTR Calculator Email CTOR Calculator Email Conversion Rate Calculator Email Bounce Rate Calculator Email Unsubscribe Rate Calculator Email Marketing ROI Calculator 
Email Open Rate 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.