Cost per Email Calculator

The calculation itself

Cost per email is the total cost of running the channel divided by emails sent: (platform + production + design + acquisition amortised) ÷ emails sent.

Platform pricing is usually tiered by subscriber count rather than by send volume, so the cost per email falls as frequency rises, which is a genuine argument for mailing more often, within engagement limits.

Production cost per email falls the same way, since a campaign costs roughly the same to produce whether it goes to 5,000 people or 50,000.

The same thing with real figures

A platform at $340 a month for 12,000 subscribers, with 24 hours of production time at $45, $1,420 of monthly cost.

At four campaigns a month to the full list, 47,280 emails are sent and the cost per email is $0.030. At eight campaigns it is 94,560 emails and $0.015.

Against $0.065 of contribution per email, the cost is 46% of contribution at four sends and 23% at eight, provided the extra sends hold their revenue per email, which they partly will not.

The break-even on an additional send is where its contribution exceeds the marginal production cost plus the future value of the subscribers it costs.

The catch

Nearly all the cost is fixed, so cost per email is largely a function of how often you send rather than of anything about the emails. A low figure can simply mean a high-frequency programme rather than an efficient one.

Platform pricing tiers also step rather than scale, so growing a list past a threshold can raise the monthly cost sharply with no change in activity.

Applying it

Judge the channel on contribution per email against cost per email rather than on either alone. The spread between them is what the programme earns.

Then check the platform tier before a list clean. Removing dormant subscribers frequently drops the account into a cheaper tier, which is a direct saving on top of the deliverability benefit.

Where the production cost actually sits

For most small businesses the platform fee is trivial and the time is not. Twenty-four hours a month of writing, designing, building and testing is the real cost, and it does not fall with automation of the sending.

The way to reduce it is templates and automation flows rather than faster campaign production: a welcome sequence, an abandoned cart flow and a post-purchase sequence are built once and run continuously.

Those automated flows typically generate a disproportionate share of email revenue, commonly a third or more from a small fraction of the sends, because they arrive at the moment of highest intent. A programme that has not built them is spending its time on the lower-yielding half of the channel.

Platform migration costs are worth modelling before a tier increase forces the question, because moving a list means rebuilding automations, templates and integrations rather than exporting a file.

Businesses that migrate to save a subscription fee frequently spend more in rebuild time than the saving returns in a year.

Template reuse is where most of the production time is recovered, and a small library of modular blocks removes the largest recurring cost in the channel.