Email Open Rate Calculator

What this calculator does

This email open rate calculator is built for the moment you need a defensible number — quoting a client, comparing options, or checking someone else's math — not a generic estimate.

Open rate is % of delivered emails that were opened.

Inputs required: 2

Runs entirely in your browser — no data leaves your device.

Includes a copy-ready summary and printable PDF view.

Formula and worked example are shown in plain language below.

How to use the Email Open Rate Calculator

Enter your values in the fields on the left.
Results update automatically.
Use the action buttons to copy, share or print.

The formula

Open Rate = Opens / Sent × 100%

Worked example

4,000 / 20,000 = 20%.

Common mistakes

Counting sent not delivered
iOS Mail Privacy inflating opens
Ignoring engagement over opens

When to use it

Use for email campaign health.

Pro tips for the Email Open Rate Calculator

The chart updates live — drag values up and down to build intuition for how the formula behaves.
Change one input at a time to see which lever actually moves the answer the most.
Round-trip check: reverse the inputs to confirm the formula matches what you'd compute by hand.

Frequently asked questions

›Good open rate?

Industry average 20–30%.

›iOS impact?

Apple pre-fetches; opens are inflated since 2021.

›Improve?

Better subject lines, sender name, timing.

›List hygiene?

Remove non-engagers quarterly.

›A/B test?

Test one variable at a time.

›Is the Email Open Rate Calculator free to use?

Yes. Every calculator on CalcPilot, including the Email Open Rate Calculator, is free with no sign-up, no watermark, and no export limit.

›Does the Email Open Rate Calculator store the numbers I enter?

No. All math runs locally in your browser — nothing is sent to a server, and closing the tab discards the inputs unless you save them to favorites.

Embed this calculator

Drop the Email Open Rate Calculator into your own site or blog post. Free to use — a small “Powered by CalcPilot” link is appreciated.

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