Email Open Rate Calculator

Work out what share of delivered emails were opened, the first gate in any email funnel.

About Email Open Rate Calculator

The open rate is the share of emails delivered that emails opened represents, expressed as a percentage. The same figure is also shown per 1,000 and as a "one in every N" odds statement, which is easier to reason about when the rate is very small. Absolute counts hide scale — a rate normalises the number so you can compare periods, channels or cohorts of different sizes, where higher is better.

Formula

Email Open Rate

Open Rate = Emails opened ÷ Emails delivered × 100

Emails opened: The subset being measured
Emails delivered: The full population it is drawn from

Worked example

With the default values below, Email Open Rate Calculator returns Open Rate of 23.00%. Change any input above and every figure here is recalculated in your browser.

Inputs used

Emails openedminimum 0: 4,600
Emails deliveredminimum 0: 20,000

Results

Open Rate: 23.00%
Remaining (whole minus part): 15,400
Equivalent per 1,000: 230.0
One in Every: 4.3

Step by step

1Values used
2Email Open Rate
3Open Rate= 23.00
4Remaining (whole minus part)= 15,400
5Equivalent per 1,000= 230.0
6One in Every= 4.3

Assumptions and limits

The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
This is an estimate for general information and not professional financial, tax or legal advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is Email Open Rate calculated?

Open Rate = Emails opened ÷ Emails delivered × 100 The open rate is the share of emails delivered that emails opened represents, expressed as a percentage. The same figure is also shown per 1,000 and as a "one in every N" odds statement, which is easier to reason about when the rate is very small.

Why does Email Open Rate matter?

Absolute counts hide scale — a rate normalises the number so you can compare periods, channels or cohorts of different sizes, where higher is better.

What values do I need to enter?

This calculator takes 2 inputs: Emails opened, Emails delivered. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.