How long until a subscriber pays for itself?

For businesses that sell a monthly plan: what it costs to acquire a subscriber, how many monthly fees that equals and in which month the accumulated base covers the investment. With platform taxes inside the math.

Simulate your subscription operation

Every assumption is yours and stays visible. Advanced fields are optional — without them the math is in gross revenue, and the tool says so.

With several plans, use MRR ÷ active subscribers (ARPU). With a single plan, that plan's fee. The best-selling plan understates the base whenever higher tiers exist.

The net amount that actually runs as ads, before taxes. Platform taxes go in the advanced field below.

How much each visit from the ad costs, on average. It is in your platform report.

Out of every 100 visits from the ad, how many become a paid subscription — not a free signup or trial start. Cold traffic on a subscription checkout usually lands between 1% and 4%.

Everything spent to bring a subscriber in besides media: agency or team, creative production, tools, commissions. Leave zero if there is none.

Advanced — optional, and what changes the verdict

Without retention and margin you can measure acquisition cost, but you cannot claim it is profitable. Fill in what you know.

Not a tax rate: it is how much the cash outlay rises to keep the net media you want. In Brazil, Meta charges PIS 1.65% + COFINS 7.60% + ISS 2.90% calculated inside the total (12.15% of it), which equals ~13.83% on top of net media. Other platform or country, adjust it. Zero shows net media only.

How much of the base cancels every month. Filling this adjusts lifetime automatically (and vice versa), so the two never tell different stories.

What is left of the monthly fee after the cost of serving the customer. With this field, coverage stops being revenue and becomes economic.

How long a subscriber stays, on average. Filling this adjusts churn automatically (lifetime = 1 ÷ churn).

How the math works

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Spend becomes subscribers

Spend divided by cost per click gives the visits; visits times page conversion give the new subscribers of the month.

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Real cost includes tax and management

Media CAC is what the platform shows. Operation CAC adds platform taxes and management cost — what the company actually spends per subscriber.

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Recurrence stacks cohorts

In month one a single cohort pays; in month six, six cohorts pay at the same time — minus whoever cancelled along the way. That is why coverage only makes sense with retention entered.

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Retention and margin decide

Without them the number is gross revenue. With them the math becomes economic — and only then can you claim acquisition pays for itself.

The formulas, exactly as they are in this page's code

visits/month          = ad spend ÷ cost per click
new subscribers/month = visits × page conversion
taxes                 = ad spend × uplift %
investment/month      = spend + taxes + management and other costs

media CAC             = spend ÷ new subscribers
operation CAC         = investment ÷ new subscribers
gross monthly fees    = operation CAC ÷ ARPU
economic payback      = operation CAC ÷ (ARPU × margin)

subscriber lifetime   = lifetime entered  (= 1 ÷ churn)
value per month       = ARPU  (× margin, when provided)
subscriber value      = value per month × lifetime

base coverage (requires retention):
  base(month) = base(month-1) × (1 - churn) + new subscribers
  accumulate revenue = base × value per month   until it matches total investment

Coverage is simulated month by month, capped at 60 months, and is only calculated when churn or lifetime is provided — without retention the math would assume nobody ever cancels. If it is not reached within the cap, the tool answers that it does not cover.

Is your sale not recurring?

This calculator assumes the customer pays every month and that the subscription closes on the page itself. If your sale is one-off, or if a sales conversation sits between the visit and the sale, the math is different.

CPA and ROAS calculator → | What is better conversion worth →

Frequently asked questions

What is the difference between media CAC and operation CAC?

Media CAC is spend divided by subscribers acquired — the number your ads platform reports. Operation CAC also adds what left the bank account to bring that subscriber in: the taxes the platform charges and the cost of managing the campaigns. It is always higher, and it is the one to compare against customer value. Neither includes your internal service and operating costs.

Why do platform taxes belong in the math?

Because in Brazil ad billing comes with PIS, COFINS and ISS on top. On Meta that is 1.65% + 7.60% + 2.90% calculated over the total charged, roughly 13.83% over the media that actually runs. Paying 3,000 thinking it is 3,000 of advertising actually delivers about 2,635. The field is editable: set it to zero to see net media only, or adjust it to your reality.

Why does the tool refuse to say it is profitable when I skip retention and margin?

Because it could not say so honestly. To start advertising and measure what a subscriber costs, those numbers are not required. But claiming an acquisition cost is profitable requires knowing how long the customer stays and how much of the fee survives the cost of serving them. Without that, the tool shows the math in gross revenue and says the verdict depends on those two numbers.

What does it mean for the base to cover the investment in X months?

It is the month when everything the base has paid so far matches everything invested up to that point. Because each cohort of subscribers keeps paying in the following months, accumulated revenue grows faster than the investment, which stays constant. This number only appears once you enter churn or lifetime: without retention the simulation would assume nobody ever cancels and the horizon would come out optimistic. Careful: coverage in gross revenue is not profit — it only becomes economic return when you enter the contribution margin.

Are these numbers a forecast?

No. They are the arithmetic result of the assumptions you typed. Cost per click, page conversion and churn move with offer, audience, seasonality and auction competition. The tool exists to test scenarios and find which assumption has to change for the math to work — not to promise a result.

Math works? Now it has to be executed.

The simulation tells you what you can pay per subscriber. Driving cost per click down, improving page conversion and moving the operation towards that break-even point is the work we do.