Plain-language questions
Ask for email open rate per month, customer or product in the SQL Explorer with AI. The AI writes the SQL, you see the query and run it yourself; the AI only receives metadata.
KPI · Marketing
Email open rate: formula and example.
Email open rate is the number of unique recipients who open an email, divided by the number of emails delivered. It gives an indication of how well your subject line, sender name and send time perform. Because some email apps register opens automatically, open rate has become less reliable than it used to be.
Email open rate formula
Number of unique opens ÷ number of emails delivered × 100%
Worked example
In September, Acme Groothandel sent a newsletter to 12,500 addresses. Of these, 12,000 were delivered and 4,200 opened. The open rate is 4,200 ÷ 12,000 × 100% = 35%.
Fictitious figures for Acme Groothandel, a sample wholesaler.
How to read this KPI
A higher open rate means more recipients open your email. Since privacy features in Apple Mail and other apps load emails automatically, the measured open rate is often higher than reality. Use it mainly to compare subject lines and send times with each other, and rely on clicks for firmer conclusions.
Pitfalls with email open rate
- Dividing by emails sent instead of emails delivered.
- Counting total opens instead of unique opens, so one recipient counts several times.
- Drawing conclusions from open rate without allowing for automatically registered opens.
SQL & DAX
Calculating email open rate in SQL and DAX
Two examples on a fictitious data warehouse for Acme Groothandel: a PostgreSQL query and a measure for a Power BI model. Adjust table and column names to your own model.
SELECT campaign_id,
sent_at::date AS sent_date,
sent, delivered, opens,
ROUND(100.0 * opens / NULLIF(delivered, 0), 1) AS open_rate_pct
FROM email_campaigns
WHERE sent_at >= current_date - interval '6 months'
ORDER BY sent_at DESC;Email Open Rate =
DIVIDE(
SUM(EmailCampaigns[Opens]),
SUM(EmailCampaigns[Delivered])
)In ENABLE
Tracking this KPI in ENABLE
In your Power BI dashboard
Define the KPI as a measure in your Power BI model and show it in the portal, with "Last refreshed" next to it. Access profiles and optional row-level security decide who sees which figures.
Custom dashboards (pilot)
Add the KPI as a tile to a custom dashboard, compared with last year. The Dashboard Builder is a pilot and can be switched on per client.
Monthly targets
With the built-in Targets app you set a target for the KPI per month, so you see actuals and target side by side.
FAQ
Frequently asked questions
How do you calculate email open rate?
Divide the number of unique opens by the number of emails delivered and multiply by 100%. With 4,200 opens from 12,000 delivered emails, the open rate is 35%. Most email tools calculate this figure automatically.
Why has email open rate become unreliable?
Open rate is less reliable because some email apps, such as Apple Mail with its privacy protection, load images, and with them the tracking pixel, automatically. An email then counts as opened even if the recipient never looked at it. Click rate is therefore a better measure of genuine interest.
What is the difference between open rate and click rate?
Open rate measures how many recipients open the email, while click rate measures how many click a link. Open rate mainly reflects the subject line and sender, click rate the content. Both are divided by the number of emails delivered.
Further reading
- KPI libraryMarketing KPIs: formulas and examplesMarketing KPIs set reach, cost and conversion side by side. They become truly useful once you link ad and web data to leads and revenue from your CRM and accounting system.Read more
- ResourcesHow to build a KPI dashboard: steps and examplesA KPI dashboard is an overview of the key figures you use to steer towards your goals, such as revenue, margin, on-time delivery or absenteeism. A good KPI dashboard does not start with the software, but with the decisions it needs to support. You then choose a limited number of KPIs, define them, sketch the dashboard and only then build it.Read more
- SolutionPower BI dashboard portal: share dashboards securelyShare your Power BI dashboards securely in your own portal, with role-based access.Read more
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