Email Frequency Profit Calculator
More email is not more money. Every extra weekly send earns a little less and fatigues your list a little more, so revenue follows a curve with a peak — and a cliff. Enter three numbers and this calculator finds the cadence that maximizes revenue, and shows what over- or under-mailing is costing you each month.
Email revenue does not rise forever with frequency. Each additional weekly send reaches a slightly more fatigued audience, so it earns a fraction of the one before it — and total revenue rises, peaks, then falls. The peak sits where the gain from one more send equals zero, which for a fatigue retention rate f is about minus one divided by the natural log of f. This calculator computes that revenue-maximizing weekly cadence from your list size, revenue per email, and fatigue rate, then shows the monthly revenue you gain by moving to it.
Email Frequency Profit Calculator inputs and result
How to use this calculator
- Enter your active list sizeUse engaged subscribers only — people who open or click. Dead addresses depress the math and your deliverability.
- Set your list’s fatigue ratePick an engagement level to load a retention rate, then tune it. It answers one question: how much does each extra weekly send earn versus the one before?
- Add revenue per email and current cadenceRevenue per email from a low-frequency period, and how many times a week you send now.
- Read your revenue-maximizing cadenceThe headline is the weekly frequency that maximizes total revenue; the sub-metrics compare your current and optimal monthly revenue.
- Move toward the peak, then exportIf you are over the peak, cutting back raises revenue; if under, add segmented sends. Copy a share link or export the CSV.
RGM Expert Says
Almost every email program we inherit is run on a hidden assumption that more sends mean more revenue, so the calendar fills up until opens sag and someone blames the creative. The truth is that frequency has a peak. Each extra weekly send lands on a slightly more tired audience and earns a fraction of the last, so revenue rises, tops out, and then falls — and most brands are sending well past the top without knowing it.
What makes over-mailing expensive is the part that does not show up in this week’s revenue. Beyond the peak you are buying small near-term gains by spending deliverability and engagement, the two assets that decide whether next quarter’s sends reach the inbox at all. We have raised total revenue for several brands by sending less, because pulling back off the cliff restored open rates and inbox placement faster than any subject-line test could.
The way to actually move the peak rightward is not volume, it is variety. A list tolerates more frequency when each send is genuinely different — segmented, triggered, useful — rather than the same broadcast offer on repeat. So we treat the optimal cadence this tool returns as today’s ceiling under today’s sameness, and we earn a higher ceiling by making the extra sends worth opening.
How it works
Total weekly revenue equals list size times revenue per email times the number of sends, but each send is discounted by the fatigue rate raised to a power: the second send earns f times the first, the third earns f-squared, and so on. That product rises then falls, and its peak — where one more send adds nothing — falls at about minus one over the natural log of f. The tool computes revenue at your current cadence and at that peak, then annualizes the monthly difference.
- f — revenue retention per extra send (e.g. 0.80); the fatigue rate.
- n — sends per week.
- Rev/email — revenue per email at a baseline low cadence.
- n* — the revenue-maximizing weekly cadence.
The exponential-fatigue model is a planning approximation; real curves vary by segment and season. Find your own peak by testing cadence on a holdout, and re-run with the observed retention rate. See RGM’s email field guide.
Why frequency has a peak, and why most brands are past it
Sending is nearly free, which is exactly why it gets abused. When the marginal cost of one more email is almost zero, the incentive is to keep adding sends, and the calendar fills until the program is broadcasting daily to people who signed up for a weekly note. The cost was never the send fee; it is the fatigue, and fatigue does not appear on the same report as the revenue, so the damage compounds unseen.
The math is unforgiving in a useful way. Because each extra send earns a constant fraction of the one before, total revenue traces a clean curve with a single peak, and past that peak every additional send subtracts more in fatigue and lost deliverability than it adds in clicks. Knowing where your peak sits turns frequency from a gut argument into a number you can defend, and it is almost always lower than the current calendar.
The deepest reason to respect the peak is that deliverability is a shared, slow-to-rebuild asset. Over-mailing lowers engagement, engagement signals drive inbox placement, and once placement slips even your good sends land in spam. Brands that send at or just below the peak protect the one thing that makes the whole channel work, which is why the highest-revenue email programs are usually not the highest-volume ones.
Frequency & fatigue benchmarks
Starting points only — your peak depends on list health, segmentation, and offer. Test to confirm.
| Signal | Typical pattern | What it means |
|---|---|---|
| Retention per extra send | ~70% to 90% | Higher = healthier list, higher peak |
| Engaged-list peak | ~4 to 6 / week | With genuine variety per send |
| Fatigued-list peak | ~2 to 3 / week | Same blast on repeat tires fast |
| First over-mailing signal | Open rate slides as volume rises | You are at or past the peak |