Calculate email open rate from unique opens and delivered messages. Use it to turn your own business data into a clear result without building a spreadsheet.
Email Open Rate Calculator
Test a different scenario
Change any scenario value below. Your original calculation stays unchanged.
Scenario calculations use the same formula and v2.5 validation rules as the main calculator. No scenario values are sent to Borkish.
Calculations and What-If scenarios run in your browser. Borkish does not require you to submit these values to calculate the result.
What the Email Open Rate Calculator measures
Open rate provides a basic indicator of subject-line and sender recognition performance. Measure list performance, campaign efficiency and customer communication metrics.
The result is most useful when every input uses the same definitions and reporting period. This keeps comparisons between campaigns, products, customers or time periods meaningful.
When to use this calculator
- Use the Email Open Rate Calculator to review campaign or list performance using one reporting period.
- Compare email efficiency before changing frequency, targeting or creative.
- Connect communication activity with revenue, retention or customer outcomes.
Formula
Percentage results are most useful when the numerator and denominator come from the same population and reporting period.
How to use this calculator
- Unique Opens — enter the value from the same report, forecast or business period as the other inputs.
- Delivered Emails — enter the value from the same report, forecast or business period as the other inputs.
- Select Calculate. The result updates immediately.
- Compare the output with a previous period, target or relevant internal benchmark before making a decision.
Worked example
Using the demonstration values — Unique Opens = 4000, Delivered Emails = 10000 — the calculator returns 40%. This example exists only to show how the formula behaves. Replace every demonstration value with your own data before using the result for planning or analysis.
How to interpret the result
Open rate provides a basic indicator of subject-line and sender recognition performance. These calculators work best with numbers from the same email campaign, CRM report or reporting period.
A stronger or weaker result does not always mean the underlying business is healthier or worse. Check the definition of Unique Opens, Delivered Emails, the attribution or accounting rules behind those inputs, and any costs or outcomes that the formula does not include.
Common mistakes to avoid
- Using Unique Opens and Delivered Emails from different reporting periods or definitions.
- Combining data from different campaigns or list segments.
- Treating opens or clicks as revenue without a clear attribution rule.
Frequently asked questions
What does this calculator do?
Calculate email open rate from unique opens and delivered messages.
Where should I get the input values?
Use your own advertising platform, ecommerce system, accounting report, CRM, analytics platform or forecast—whichever system is authoritative for the metric. Keep all inputs on the same basis and date range.
Is there one good result I should target?
Usually not. A useful target depends on your margins, acquisition model, operating costs, channel, market and business goals. Your own historical performance is often a better starting benchmark than a generic number.
Can I use this for forecasting?
Yes. Enter forecast values to model a scenario, but treat the output as an estimate based on those assumptions rather than a prediction of future performance.
For details about formulas, rounding and limitations, see our Calculator Methodology.