SaaS affiliate commission calculator
Compare three commission durations for one new paying customer. See how retention, refunds and service costs change the contribution left over.
Your inputs stay in this browser. No account is required. Defaults are illustrative assumptions, not industry benchmarks.
One acquired customer over 24 months
Expected revenue after refunds: $1,387.70. Contribution below is after modeled service costs and affiliate commissions, before fixed overhead, taxes and program costs.
| Offer | Commission cost | Contribution |
|---|---|---|
| First invoice only | $19.60 | $1,090.56 |
| First 12 months | $180.18 | $929.98 |
| Recurring within horizon | $277.54 | $832.62 |
| Month | Retained probability | Net revenue | First invoice | Capped | Recurring |
|---|---|---|---|---|---|
| 1 | 100.00% | $98.00 | $19.60 | $19.60 | $19.60 |
| 2 | 95.00% | $93.10 | $0.00 | $18.62 | $18.62 |
| 3 | 90.25% | $88.45 | $0.00 | $17.69 | $17.69 |
| 4 | 85.74% | $84.02 | $0.00 | $16.80 | $16.80 |
| 5 | 81.45% | $79.82 | $0.00 | $15.96 | $15.96 |
| 6 | 77.38% | $75.83 | $0.00 | $15.17 | $15.17 |
| 7 | 73.51% | $72.04 | $0.00 | $14.41 | $14.41 |
| 8 | 69.83% | $68.44 | $0.00 | $13.69 | $13.69 |
| 9 | 66.34% | $65.02 | $0.00 | $13.00 | $13.00 |
| 10 | 63.02% | $61.76 | $0.00 | $12.35 | $12.35 |
| 11 | 59.87% | $58.68 | $0.00 | $11.74 | $11.74 |
| 12 | 56.88% | $55.74 | $0.00 | $11.15 | $11.15 |
| 13 | 54.04% | $52.96 | $0.00 | $0.00 | $10.59 |
| 14 | 51.33% | $50.31 | $0.00 | $0.00 | $10.06 |
| 15 | 48.77% | $47.79 | $0.00 | $0.00 | $9.56 |
| 16 | 46.33% | $45.40 | $0.00 | $0.00 | $9.08 |
| 17 | 44.01% | $43.13 | $0.00 | $0.00 | $8.63 |
| 18 | 41.81% | $40.98 | $0.00 | $0.00 | $8.20 |
| 19 | 39.72% | $38.93 | $0.00 | $0.00 | $7.79 |
| 20 | 37.74% | $36.98 | $0.00 | $0.00 | $7.40 |
| 21 | 35.85% | $35.13 | $0.00 | $0.00 | $7.03 |
| 22 | 34.06% | $33.38 | $0.00 | $0.00 | $6.68 |
| 23 | 32.35% | $31.71 | $0.00 | $0.00 | $6.34 |
| 24 | 30.74% | $30.12 | $0.00 | $0.00 | $6.02 |
How the model works
For month m, retained-customer probability = (1 − monthly churn ÷ 100)m − 1. Month 1 starts with one paid customer. Net revenue = monthly price × retained probability × (1 − refund percentage ÷ 100).
Commission = net revenue × commission rate ÷ 100, during the selected earning period. The first-invoice offer pays only in month 1; the capped offer pays through the chosen duration; the recurring offer pays through the model horizon. Each uses the same rate. A one-time fixed bounty is not modeled.
Contribution = net revenue × gross margin ÷ 100 − commission. Your gross margin input should reflect service costs before affiliate commissions. This model assumes costs scale with net revenue; it does not model nonrefundable fees or service costs retained after refunds separately.
Read the result as a scenario
Churn is a constant monthly probability, refunds reduce each month's commission base, and the model adds no new customers. There are no upgrades, price changes, annual prepayments, reactivations or tax calculations. Software fees, recruitment costs and fixed overhead are excluded. Contribution is not profit or a guarantee of future results.
Calculations use full precision; displayed currency and exported currency columns round to two decimals. Displayed monthly amounts may not sum exactly to the displayed total. The CSV records your assumptions and every month's contribution for each offer.
Choose an offer you can explain
Try a lower-margin or higher-churn case before setting your rate. Then read how to choose commission rates and use the launch checklist to connect the offer to tracking and payout rules.
Stripe's monthly churn explanation provides background on the churn input. The finite-horizon formulas here are our own explicit planning assumptions. Formula version 1 · Reviewed 13 September 2026.