Decomposes your active user base each period into new, retained, resurrected, and churned. It makes one thing impossible: hiding behind top-line growth without understanding its quality.
▸ Try the interactive toolGrowth accounting decomposes a product's active user base, each period, into four components: new users, retained users, resurrected users, and churned users. It exists to make one thing impossible — hiding behind top-line growth without understanding its quality.
A product can show rising active users while quietly hemorrhaging existing ones, masking the churn with new acquisition. Growth accounting exposes this by showing the composition of growth: are your active users growing because you're retaining people (healthy) or because you're acquiring faster than you're churning (a treadmill that eventually fails)? The key derived measure is the quick ratio — roughly, how many users you gain (new + resurrected) for each you lose (churned) — which reveals whether growth is durable or borrowed.
Each period, active users = new + retained + resurrected − churned.
Quick ratio ≈ (new + resurrected) ÷ churned — how many users gained per user lost. Above ~1 means growing; well above means durable.
Top-line active-user growth can hide a leaky bucket — a product churning heavily but acquiring fast enough to mask it, until acquisition slows and the truth surfaces.
| The shortcut | What it costs | What it gives you instead |
|---|---|---|
| Hiding behind top-line growth | Rising actives mask heavy churn underneath. | Decomposition exposes whether growth is retention or acquisition. |
| The leaky bucket | Acquiring fast while churning faster; collapse when acquisition slows. | The quick ratio reveals gained-per-lost durability. |
| No churn visibility | Churned users vanish from the top-line number. | Growth accounting makes churn an explicit component. |
| Mistaking acquisition for health | Growth that's all new users isn't sustainable. | The composition shows whether growth is healthy. |
For each period, sort active users into new (first time), retained (active last period too), resurrected (returned after a gap), and churned (active before, gone now).
See how much of your active-user change comes from each bucket. Growth dominated by new users with heavy churn is fragile; growth from retention is durable.
Divide gains (new + resurrected) by losses (churned). Above ~1 means you're growing; the higher above, the more durable. Below 1 means you're shrinking despite any top-line illusion.
Read the composition: is the product retaining well and growing on top, or churning heavily and running to stand still? The buckets tell you which lever (retention vs. acquisition) needs work.
Heavy churn? Fix retention before pouring in acquisition (a leaky bucket can't be filled). Strong retention but low new? Acquisition is the lever. The decomposition directs the effort.
A product's active-user count was rising steadily, and the team felt confident. Growth accounting told a more sobering story: the growth was almost entirely new users, while churn was quietly high — they were acquiring fast enough to mask a serious retention problem. The quick ratio was barely above 1, meaning they were gaining only slightly more than they lost.
The decomposition made the leaky bucket impossible to hide. Pouring more acquisition into the product would have been filling a leaking bucket faster; the real fix was retention. Once they addressed why existing users were churning, the same acquisition produced durable growth instead of a treadmill — and the quick ratio climbed well above 1.
The deliverable is each period's active users decomposed into the four components, with the quick ratio — a clear read on growth quality.
| Component | Meaning | Healthy sign |
|---|---|---|
| New | First-time actives | Steady inflow |
| Retained | Active again this period | High — the durable core |
| Resurrected | Returned after a gap | Win-backs working |
| Churned | Were active, now gone | Low — the leak |
Growth accounting answers the question top-line numbers dodge: what kind of growth is this? It decomposes a single reassuring number into a story about retention, churn, and durability — and the story is often less flattering than the headline.
The leaky-bucket insight is the one that changes behaviour. A product can grow its active-user count for a long time on acquisition alone while churning heavily underneath, and the top-line number gives no warning — right up until acquisition plateaus and the accumulated churn surfaces all at once. The quick ratio is the early-warning gauge: it shows how many users you gain per user lost, exposing a treadmill long before it collapses. And the decomposition is directly actionable, because it tells you which lever to pull — heavy churn means fixing retention must come before scaling acquisition, since pouring users into a leaky bucket only wastes them faster. It's the quantitative backbone behind 'retention is the foundation of growth.'
Rising actives can mask heavy churn. Decompose into the four components.
Filling a leaking bucket faster wastes users. Fix churn first.
It's the durability gauge. A ratio barely above 1 is a warning, not a win.
Acquisition-driven and retention-driven growth are very different. Read the composition.
It breaks down the top-line metric the Measurement Hierarchy (Tool 02) might otherwise show flat.
Growth accounting shows composition; retention curves (Tool 08) show the shape of retention over time.
It's the numeric backbone of 'fix retention before acquisition' — connecting to Module 2's expansion and economics.
Growth quality informs whether North Star growth is durable (Tool 04).
Imagine a product whose active users rose 10% this period. Sketch two ways that could happen: one healthy (retention-driven), one fragile (acquisition masking churn).
For each, estimate roughly what the quick ratio would look like — and which lever (retention or acquisition) you'd tell the team to pull.
If you can see how the same 10% growth could be durable or a leaky bucket depending on composition, you've grasped why top-line numbers lie — and why growth accounting decomposes them.