LTV Calculator: LTV, CAC Payback and the Most You Can Pay Affiliates

Enter your revenue per account, gross margin, churn and acquisition cost. You get customer lifetime value, LTV:CAC and CAC payback, then the highest recurring commission percent and the largest one-time bounty that still earn a new customer back inside the payback target you set. Built for SaaS founders sizing an affiliate program.

Affiliate limits at your target

Max recurring commission: 20.0%
Max one-time bounty: $100

LTVARPA x margin / churn: $1,306.67
LTV:CAC: 4.36 : 1
Payback, simpleCAC / monthly gross profit: 7.7 mo
Payback, churn-adjustedExpected cohort profit reaches CAC: 8.6 mo
Expected customer lifetime1 / churn: 33.3 mo

Create a program at this rate

How to use it

Enter revenue and margin. Type your average revenue per account per month (ARPA) and your gross margin as a percent.
Enter churn and CAC. Add monthly customer churn as a percent and your acquisition cost per customer, leaving out any affiliate commission.
Set the payback target. Choose the number of months in which a new customer should earn back what it cost to win.
Read the limits. The results show LTV, LTV:CAC, payback, the highest recurring commission percent and the largest one-time bounty that still meet the target.
Copy or download the CSV. Use Copy CSV or Download CSV to paste the inputs and results into a spreadsheet or a planning doc.

How the numbers are calculated

Every figure comes from the five numbers you enter. Nothing is assumed from an industry average. Let m = ARPA x gross margin (gross profit per account per month) and c = monthly churn as a decimal.

LTV = m / c. Expected lifetime in months is 1 / c.
LTV:CAC = LTV / CAC.
Simple payback = CAC / m months. It assumes the customer never leaves.
Expected profit in n months = m x (1 - (1 - c)^n) / c. This counts a customer as paying in month one and surviving each later month with probability 1 - c. Churn-adjusted payback is the n at which this equals CAC, which solves to n = ln(1 - CAC x c / m) / ln(1 - c). If CAC x c / m is 1 or more, a cohort never earns its cost back.
Max recurring commission = gross margin - CAC / (ARPA x f), where f = (1 - (1 - c)^T) / c is the expected number of paid months inside your target T. Commission is paid on every payment while the customer stays, so each paid month contributes ARPA x (margin - commission). Setting the cohort total over T months equal to CAC gives this rate.
Max one-time bounty = m x f - CAC, never below zero. A bounty is paid once, so it adds to CAC, and the cohort must still earn back CAC plus bounty within T.

Limits to keep in mind: churn is treated as a constant monthly rate, and revenue is treated as flat per account. If your churn is high in month one and low later, or customers expand, the real picture differs. Use the target and the CAC field to test the cases that matter. Enter CAC without commission; the commission is what the result solves for.

Questions, answered

How do you calculate customer lifetime value for a subscription?

Multiply average revenue per account per month by gross margin, then divide by monthly churn. At $49 ARPA, 80% margin and 3% churn that is 49 x 0.80 / 0.03 = $1,306.67. The result is gross profit, not revenue, which is why margin is an input.

What is CAC payback and how is it different from LTV:CAC?

CAC payback is how many months of gross profit it takes to recover the cost of winning a customer. LTV:CAC compares total lifetime profit to that cost. Payback tells you how long cash is tied up. LTV:CAC tells you whether the customer is worth winning at all.

Why does the calculator show two payback numbers?

Simple payback is CAC divided by monthly gross profit and assumes the customer stays. Churn-adjusted payback uses the expected profit across a cohort in which some customers leave each month, so it is longer whenever churn is above zero.

What does the maximum recurring commission mean?

It is the highest percent of each payment you can pay an affiliate, for as long as the customer stays subscribed, while the cohort still earns back its CAC within your target. It comes from gross margin minus CAC divided by the revenue expected inside the target window.

What should I enter as CAC if the affiliate is the only channel?

Enter the acquisition cost that is not commission, such as onboarding, free-trial servicing or the time you spend on the partner. If there is none, enter 0 and the maximum recurring commission becomes your gross margin, which is the point where each customer contributes nothing.

Is my data sent anywhere?

No. Every calculation runs in your browser. Nothing is stored or transmitted.

Run the program at the rate you chose

Ambassly tracks referrals through Stripe, books each commission in an append-only ledger, applies hold periods and refund clawbacks, and exports payouts. Set the rate you just calculated and invite your first affiliates.