Help

Product costs

Updated October 21, 2026

Why it matters

Olympus works out two margins from your Shopify data:

• CM1 (contribution margin before ads): your sales, less product costs, Shopify shipping labels and Shopify Payments fees. What each sale leaves to pay for ads and everything else.
• CM2: CM1 less your ad spend. What's left after marketing, and the number Olympus ranks first when it tells you how the business is doing.

Product costs are usually the biggest thing coming off. Olympus reads them from Shopify's Cost per item, and a product sold without one counts as costing nothing, so every margin built on it reads too high: CM1, CM2, your break-even ROAS and CPA, and profit by product.

What to put in Cost per item

The cost of one unit, landed and ready to ship. Most stores build it from three parts:

1. What you pay your supplier for one unit.
2. Getting it to you: freight, duties and tariffs for a shipment, divided across the units in it. A best guess per unit is fine.
3. Packaging that goes with each unit: its box, bag, label or insert. For packaging you use once per order, like a mailer, an average per unit is close enough.

It won't be perfect, and it doesn't need to be. A cost within a few percent gives you margins you can make decisions on. A missing one doesn't.

Then tell Olympus which it is, in Settings, Product costs: landed, or the unit price only. Your AI reads the answer before it quotes a margin.

What to leave out

Olympus counts these separately, so putting them in Cost per item would count them twice:

• Shipping to your customers. Olympus takes the labels you buy in Shopify off CM1. Labels bought somewhere else aren't counted at all, so CM1 reads a little high if you use another label service.
• Payment fees. Olympus takes Shopify Payments fees off CM1. Fees from other payment methods (PayPal, for example) aren't counted.
• Ad spend. It comes off CM2, from your connected ad accounts.

And these belong in your own books, not in Olympus: rent, payroll, apps and software, and the one-off costs of running the business. Olympus stops at CM2. What's left after that, less your fixed costs, is your profit, and your accountant is the one to work it out.

Entering costs in Shopify

1. In Shopify, open Products and choose a product.
2. Under Pricing, fill in Cost per item. Shopify shows the profit and margin next to it as you type, a quick check for typos.
3. If the product has variants (sizes, colors), each variant has its own cost. Open each one, or set them all at once in the next step.

For many products at once, select them on the Products page and choose Bulk edit. Add the Cost per item column if it isn't showing, fill it in, and save.

When your costs change

Update Cost per item whenever a new order from your supplier comes in at a different price, or your freight costs move. Shopify records each sale with the cost the product had when it sold, so:

• A new cost counts from the next sale on. Sales before the change keep the old cost.
• Adding a missing cost doesn't fix past sales. Those sales stay counted at no cost, and your margins for those days stay a little high.

That's why it's worth setting a cost before a product's first sale, not after.

Checking your costs in Olympus

Every night Olympus checks your last 90 days of sales. Settings, Product costs shows what it found, each product linked to its page in Shopify:

• Sold without a cost, with whether each has one now.
• Costs that look wrong: $0, or at or above the price. If a product really costs that, ignore it.
• Highest cost share: the products whose cost is the biggest share of what they sold for. Not a mistake on its own: deep discounts raise it too.

When every cost is there, it says so in one line. Below 90% of sales with a cost, Pulse notes that CM1 and CM2 read high, and Olympus holds back your break-even lines.

A product you've just fixed stays on the list until its sales without a cost are older than 90 days. If it says it has a cost now, there's nothing left to do.

Questions? Email support@oldbones.ai.