Free tool
Affiliate commission calculator
Model what a recurring commission structure actually costs as referred customers renew and churn — monthly spend, cohort lifetime cost, and year-one totals.
Commissions modeled per paid invoice; churn shrinks the earning base each month — matching how billing-native tools actually accrue.
This month
Referred revenue
$1,600
Commissions owed
$400
One cohort, 12 months
$4,082
Total commission spend on this month’s referrals as they renew and churn out (~12.0 effective paying months).
Year 1 total
$40,409
All twelve monthly cohorts at this pace, each decaying at your churn rate.
Compare that year-one figure to what a % -of-commission platform would take on top — typically another 20–30% of these payouts — and you’ve found your software budget for the decade.
How the math works
Each month’s referred customers form a cohort earning customers × ARPU × rate in month one. In later months the cohort shrinks by your churn rate, so commission spend decays with it — exactly how billing-native affiliate tools accrue from paid invoices rather than signup events.
The year-one figure stacks all twelve cohorts. Use it two ways: as the budget line when you set your commission rate, and as the number to beat when a platform quotes you a percentage-of-commission fee — that fee lands on top of these payouts, every month, forever.
When the math works, run it on rails
Sentalong accrues commissions from real invoice events, reverses refunds automatically, and pays affiliates monthly via Stripe — flat pricing, no cut of commissions.