Calculator

Subscription Payback Calculator

Gross LTV can look healthy while the subscriber still takes too long to recover acquisition. Use this calculator to connect cycle-level contribution, retention, and CAC so the subscription gets judged on payback speed, not just on recurring revenue.

Estimate payback months from true cycle contribution
See whether modeled retention is long enough
Measure the net LTV left after CAC is actually repaid

Calculate subscription payback

Enter subscription price, cycle costs, fee drag, retention, and CAC. The result shows how long the subscriber needs to repay acquisition and how much contribution is still left after that recovery point.

Subscription price per cycle Revenue from one subscriber in a billing cycle. Product cost per cycle Direct product or service delivery cost per cycle. Fulfilment cost per cycle Shipping or fulfillment burden per cycle. Fee rate % Processor or platform rate applied to subscription revenue. Fixed fee per charge Fixed card or order fee on each rebill. Support cost per cycle Support, refund reserve, or servicing burden per cycle. Average retention months Average subscriber lifetime before churn. CAC Acquisition cost per new subscriber.

Three subscription payback scenarios.

Formula

What the subscription payback model asks

Payback months = CAC ÷ Net contribution per cycle

Net LTV after CAC = (Net contribution per cycle × Retention months) - CAC

This is a contribution payback model, not a topline subscription story. It asks whether the subscriber repays acquisition fast enough to leave meaningful retention contribution on the other side.

Where subscription CAC gets waved through

Teams anchor on recurring revenue before they know cycle-level contribution.
Retention looks healthy, but the payback window still eats most of the life.
Support and fee drag are treated as overhead instead of subscriber cost.

Where to go next

Once payback is clear, compare it against subscription margin and repeat-order recovery to decide whether the model deserves more acquisition budget.

FAQ

Subscription payback questions

What is a good subscription payback period?

It depends on cashflow, retention, and margin, but shorter payback usually creates more room to scale. The important question is whether enough retention remains after CAC is recovered.

Should I use gross or net contribution for payback?

Use net contribution per cycle after fee drag, fulfilment, support, and direct cycle costs. Gross revenue makes payback look faster than it really is.

What if retention is shorter than payback?

That is the warning signal. If modeled retention runs out before CAC is recovered, the subscriber is not paying back cleanly under the current assumptions.