Definition
Open rate measures the percentage of delivered emails that recipients opened. It is one of the most widely tracked email marketing metrics because it indicates how effective your subject line, preview text, and sender name are at capturing attention in a crowded inbox.
Email open rate is tracked using a transparent tracking pixel embedded in the email HTML. When a recipient loads the images in their email client, the pixel fires and registers an open. This means open rates are not 100% accurate — some recipients read emails with images disabled, and Apple Mail Privacy Protection automatically loads tracking pixels regardless of whether the email was opened.
Formula
Open rate is calculated using the total number of unique opens divided by the total number of delivered emails.
Open Rate = (Unique Opens / Delivered Emails) × 100
| Variable | Description |
|---|---|
| Unique Opens | Number of individual recipients who opened the email at least once |
| Delivered Emails | Total emails sent minus bounces |
Average Benchmark
Average open rates vary significantly by industry. Here are the benchmarks across key sectors:
| Industry | Average Open Rate |
|---|---|
| Agriculture | 23.4% |
| Ecommerce | 18.7% |
| Education | 25.1% |
| Finance | 20.2% |
| Healthcare | 22.6% |
| Media & Publishing | 21.9% |
| Real Estate | 24.5% |
| SaaS & Technology | 19.8% |
| Travel & Hospitality | 17.5% |
| Nonprofit | 25.3% |
Overall average across all industries: 18-22%. A good open rate for most businesses is above 20%. Rates above 30% are considered excellent but are increasingly difficult to achieve due to Apple Mail Privacy Protection and inbox changes.
How to Improve Open Rate
- Write better subject lines: Aim for 40-60 characters. Use curiosity, urgency, personalisation, and relevance. Test different approaches with A/B testing.
- Optimise sender name: Use a recognisable name rather than a generic company address. Personal sender names (e.g. "Sarah from Brand") often outperform brand-only names.
- Segment your audience: Send targeted emails to smaller, relevant lists rather than blasting your entire database. Relevant emails get opened more often.
- Clean your list regularly: Remove inactive subscribers who have not opened in 90 days. They drag down your open rate and hurt deliverability.
- Test send times: The best send time depends on your audience. Try different days and times and track which get the highest open rates.
- Use preheader text: The preview text that appears next to the subject line is valuable real estate. Use it to complement the subject line, not repeat it.
Example Calculation
If you send a campaign to 10,000 subscribers, 200 emails bounce, and 1,960 unique opens are tracked:
Delivered Emails = 10,000 - 200 = 9,800
Open Rate = (1,960 / 9,800) × 100 = 20%
This means 20% of your successfully delivered emails resulted in an open. This is right around the industry average.
Related Glossary Terms
A/B Testing
A/B testing in email marketing is the practice of sending two variations of an email to a small sample of your list to determine which version performs better before sending the winner to the remaining subscribers.
Abandoned Cart Email
An abandoned cart email is an automated message sent to customers who added items to their online shopping cart but left without completing the purchase. It is one of the highest-converting email types in ecommerce.
Abuse Complaint
An abuse complaint is a report from a recipient who marks an email as spam, which negatively affects sender reputation and deliverability.
AIDA Model for Email
The AIDA model (Attention, Interest, Desire, Action) is a classic copywriting framework used to structure email campaigns that guide subscribers from awareness to conversion.
AMP for Email
AMP for Email is a Google-developed framework that allows email messages to include interactive elements like forms, carousels, accordions, and live content. It turns static emails into dynamic, interactive experiences directly inside the inbox.
Anchoring Effect in Email Marketing
The anchoring effect is a cognitive bias where the first piece of information presented (the anchor) influences subsequent decisions, used in email to frame pricing and value perception.
Frequently Asked Questions
A good email open rate is between 18% and 22% across all industries. Rates above 25% are above average, and anything above 30% is considered excellent. However, benchmarks vary significantly by industry, audience quality, and email type.
Yes. Apple Mail Privacy Protection (MPP), released in 2021, automatically loads tracking pixels for all Apple Mail users regardless of whether they opened the email. This artificially inflates open rates. As a result, open rate is becoming less reliable as a primary metric, and many marketers now focus more on click rates and conversions.
Not necessarily. A high open rate with a low click rate may indicate misleading subject lines that drive opens but fail to deliver on the promise. Always measure open rate alongside click-through rate to understand full engagement.
Write subject lines that create curiosity or clear value. A/B test subject lines for length, tone, and personalisation. Clean your list regularly to remove inactive subscribers who drag down your open rate. Improve sender recognition by using a consistent from name and address. Send at optimal times based on your audience's behaviour patterns.
The best send time depends on your audience and industry. General studies show Tuesday through Thursday between 9am-11am or 1pm-3pm in the recipient's timezone perform well. B2B emails often perform better during business hours, while B2C emails can perform well on evenings and weekends. Test different send times with your specific audience rather than relying on general benchmarks.