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Email Open Rate Calculator

Calculate email open rate from unique opens and delivered messages.

Free business calculator

Email Open Rate Calculator

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 becomes more useful when every input follows the same definition and reporting period. That keeps comparisons between campaigns, products, customers and 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

Open Rate = (Unique Opens ÷ Delivered Emails) × 100

Percentage results are most useful when the numerator and denominator come from the same population and reporting period.

How to use this calculator

  1. Unique OpensUse the value from the same reporting period or scenario as your other inputs.
  2. Delivered EmailsUse the value from the same reporting period or scenario as your other inputs.
  3. Complete the required inputsThe result updates automatically as the values become valid.
  4. Compare the resultUse 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%. The example shows how the formula behaves; replace the demonstration data with your own before using the result for planning.

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.

Check the definition of Unique Opens, Delivered Emails, the attribution or accounting rules behind those inputs, and any important 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 source 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 formulas, rounding and limitations, see our Calculator Methodology.
Decision path

What to calculate next

Open rate provides a basic indicator of subject-line and sender recognition performance. A single metric rarely explains the whole decision, so compare this result with the related cost, conversion, margin or growth metrics below before acting on it.

Keep reporting periods and metric definitions consistent when moving between calculators. That makes the comparison more useful than treating each result as a standalone benchmark.

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