The calculator Last month, on one screen
one person buying twice is two orders, one buyer
buyers who bought again within your window (e.g. 90 days) — their earlier order can sit in a prior period, so this need not reconcile with this month's orders
Your seven numbers
Pick the one number to move this month — it's the seven-number scorecard in Digital Products: Intermediate →
How to read it Revenue per visitor is the one to steer by
Of the seven, revenue per visitor is the number that moves only when the business genuinely gets better, and it survives every change in what traffic costs. Not clicks, not followers — revenue per visitor. But do not spend against it: it is gross, the platform's cut still inside it. The figure you may spend to acquire a visitor is contribution per visitor, always smaller.
The seven formulas
- Conversion rate = orders ÷ visitors
- Revenue per visitor = revenue ÷ visitors
- Average order value = revenue ÷ orders
- Repeat-purchase rate = repeat buyers ÷ buyers (⚠️ buyers, not orders)
- Refund rate = refunds ÷ orders
- Contribution per order = average order value × (1 − fee%)
The one that trips people is the fifth. An order is not a buyer. One person buying twice is two orders and one buyer. Conversion uses orders; repeat-purchase rate uses buyers. Mixing them is how the numbers quietly lie.
A worked example
1,000 visitors, 20 orders, £575 revenue, 20 buyers, 5 who came back within 90 days, 1 refund, 6.5% fee: conversion 2%, revenue per visitor £0.58, average order £28.75, repeat rate 25%, refund rate 5%, contribution per order £26.88. That fifth line — five of the twenty buyers came back within 90 days, a later purchase that is not among this month's 20 orders — is usually the most valuable number on the sheet, because it is the one nobody else in your position is measuring.
Edge cases the calculator handles
- A month with no orders (or no visitors, or no buyers) shows "—" for any figure that would divide by zero — average order value, conversion, repeat rate — rather than £0 or an error. A blank is the honest answer when there is nothing to divide.
- The repeat rate stays believable because it divides by unique buyers, not their orders — count orders there and a loyal customer can push it over 100%.
Common questions
Why does contribution not subtract refunds?
Because refunds are already their own number (line 6). Contribution per order is what a completed sale leaves you after fees; the refund rate tells you how often a sale does not complete. Keeping them separate is how you see both, rather than blurring one into the other.
What if I do not know my unique buyers?
If every sale last month was a first-time buyer, buyers = orders and the repeat rate is simply repeat buyers ÷ orders. The moment you have returning customers, the two diverge — that is the point at which counting buyers separately starts to matter.
Can I keep a copy?
Download the scorecard spreadsheet — same seven formulas, your numbers, saved.
It is the tool at the heart of Digital Products — Intermediate, the second of three ePORTS books — the one about making the same buyer buy again.
Get the full Digital Products series →