Affiliate Commission Calculator

Understanding the affiliate commission calculator — concept and principle

Affiliate marketers, bloggers and creators earn a percentage of every sale made through their links. This calculator estimates how much commission a given amount of traffic should earn and the earnings per click (EPC), the figure most affiliate networks use to compare programmes. It works with any currency.

How it is calculated

• Sales = clicks × conversion rate.
• Commission earned = sales × average order value × commission rate.
• Earnings per click (EPC) = conversion rate × average order value × commission rate, which equals commission ÷ clicks.

Conversion rate and commission rate are entered as percentages; the average order is the basket value on which commission is paid.

The principle

The calculation follows the visitor's path: a click leads to a purchase with some probability, the purchase has an average value, and you receive a share of it. Multiplying the three gives the expected value of one click. EPC is useful because it combines conversion, basket size and rate into a single number, so a programme paying 3% on large baskets can beat one paying 10% on small, rarely bought items. Note that sales are a statistical expectation, so the calculator can show a fractional number of sales.

Worked example

1. Sales = 5,000 × 3% = 150.
2. Sales value = 150 × $45 = $6,750.
3. Commission = $6,750 × 5% = $337.50.
4. EPC = 3% × $45 × 5% = $0.0675 ($337.50 ÷ 5,000 clicks).

How to read the result

Compare EPC across programmes and with what you could earn from the same traffic elsewhere, such as display ads. If you pay for traffic, EPC must be higher than your cost per click to make money. Commission is usually paid only on approved, non-returned orders after a validation period, so actual payouts can be lower than this estimate.

Common mistakes

• Using the merchant's site-wide conversion rate instead of the rate for your own referred visitors.
• Ignoring returns, cancellations and cookie windows that void some commissions.
• Applying the commission rate to the order total when the programme excludes tax, shipping or certain categories.

Frequently asked questions

What is a good EPC?

It varies by niche and programme. Its main use is comparison: test offers on similar traffic and keep the ones with the higher EPC.

Why is my real commission lower than estimated?

Returns, cancelled orders, attribution to another affiliate and excluded products all reduce approved commissions.

Should I choose a higher rate or a higher EPC?

EPC, because it reflects what each visitor actually earns once conversion and basket size are included.

Sources: Farris, Bendle, Pfeifer & Reibstein, Marketing Metrics (Pearson) — conversion and web metrics