How Do I Connect My Site to My P&L?

Founder of Conversion Club · ikko

1 Oct 2026 · updated 19 Oct 2026 — 2 min read

Short answer

With a four-term equation: visits × conversion rate × average order value × contribution margin rate. Three of them take two clicks to find in Shopify. The fourth, the one that actually hits the P&L, is often empty.

The answer in detail

With a four-term equation: visits × conversion rate × average order value × contribution margin rate.

Multiply them and you get the month's contribution margin, the money that pays your fixed costs. Every site project should say which of these terms it moves, and by how much. Three terms take two clicks to find in Shopify. The fourth, the one that actually hits the P&L, is often empty.

The benchmark

Margin per visit sums up the equation: contribution margin divided by the number of sessions. It's the lead indicator of the Prisme, the framework we use to audit stores.

Take a hypothetical example. If each visit earns you €0.60 and you get 400,000 visits a month, a five-cent increase per visit is worth €20,000 in monthly margin.

On a brand we audited this year, revenue per visit averaged around €1.40 over two years. Its margin per visit, however, we couldn't measure, because product costs weren't filled in in Shopify.

For lack of anything better, we approximated it by assuming a 70% gross margin, and we spelled that out in black and white in the report.

The term that vanishes without warning

Shopify only calculates margin on products whose cost was recorded at the time of sale. A product with no cost doesn't break the report. It quietly drops out of it, and the margin rate shown covers only part of your sales. And a cost entered today only applies to future sales.

So before sizing any project, check coverage. Copy this into the ShopifyQL editor in your reports, then rerun it every month:

FROM sales SHOW net_sales, net_sales_with_cost_recorded, net_sales_without_cost_recorded DURING last_month

Divide the second column by the sum of the last two and you get the share of your product sales whose margin is actually known.

What to say next in the leadership meeting fits in two lines:

"Last month, our margin was measured on X% of sales. Until we reach 100%, our margin per visit remains an estimate, and I propose we fix that before we prioritize the roadmap."

The rule

No project goes on the roadmap without its term of the equation and an estimate. "Improve the experience" maps to no term, while "gain two tenths of a point of mobile conversion" names one, and can be quantified.

The steps

The bridge table. It reconciles Shopify's numbers with the accounting numbers, month by month.
The definitions. Set them with finance: excluding taxes, net of returns, sale counted at order or at delivery.
Cost coverage. Enter the purchase cost on every variant until the last column of the query shows zero.
Margin per visit. Calculate it monthly and read it as a trend.
The sizing. Estimate every project in cents of margin per visit gained.

The trap

The trap is believing you're talking about the same revenue as the finance team.

In Shopify, "total sales" include taxes and shipping, a sale is recorded on the day of the order, and a return is deducted the day it's processed, sometimes the following month.

Accounting works excluding taxes and, under chart-of-accounts rules, recognizes a sale when the goods are delivered. So an order placed on the 31st doesn't necessarily fall in the same month on both sides of the hallway.

Until that bridge is written down, every budget meeting starts with ten minutes of arguing over the numbers, and it's rarely the e-commerce team that wins the argument.