Retention curve projector
retention decides your ceiling. at a steady install rate your active users climb for a while and then stop, and where they stop is set almost entirely by how many people are still around after a month. this shows you that ceiling before you spend a year walking into it.
this calculator needs javascript. the explanation below works without it.
Where the ceiling comes from
if you add the same number of users every month and keep a fixed share of them, active users settle at new users divided by one minus the retention rate. it is arithmetic, not a forecast.
20,000 new a month at 8% month one retention settles near 21,700 active. doubling spend doubles the ceiling. doubling retention does far more, and costs nothing in media.
What the curve shape tells you
day 1 tells you whether the first session delivered what the ad promised. day 7 tells you whether there was a reason to come back. day 30 tells you whether it became a habit.
a steep fall from day 1 to day 30 with a decent day 1 usually means the product works once and has no second reason to exist. that is a product problem wearing a marketing costume, and no amount of retargeting fixes it.
Numbers tell you what. They do not tell you what to do.
bring your real numbers to the breakdown call and leave with a plan for them. free, no pitch deck.
Common questions
Is this model too simple?
yes, deliberately. it uses month one retention as a flat monthly rate, whereas real curves flatten out, so this understates your long term base. treat the ceiling as a conservative floor rather than a prediction.
What retention should I aim for?
it varies enormously by category, so chasing someone else\u2019s benchmark is a poor use of attention. the number that matters is your own trend over the last six cohorts. if it is rising, you are building something. if it is flat and low, more spend will not save it.
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Bring one real growth problem. Leave with the fix.
the breakdown call is free. no pitch deck, no agency handoff.