The invoice is not the cost
Ask most store owners what a product costs them and they will tell you what the supplier charged. It is the number on the invoice, it is the number in the spreadsheet, and it is the number the margin calculation uses.
It is also the one number that is definitely not the cost, because the unit did not teleport into your stockroom. It was shipped, possibly across a border, possibly with duty payable, handled by somebody at a port, insured on the way, and received by a person who spent time checking it against a purchase order.
All of that happened before the product was available to sell. All of it is money you spent to have a sellable unit. The supplier invoice is simply the largest single line, which is why it gets mistaken for the whole thing.
The cost that includes everything is the landed cost, and the gap between it and the invoice price is where a surprising number of stores quietly lose their margin.
What the gap looks like
Take the worked example from our glossary entry, because the arithmetic is more convincing than the argument.
You order 500 units at 8 each, so 4,000. Freight is 900. Duty is 320. Customs handling is 80. Your total outlay is 5,300 for 500 units, which is 10.60 a unit, not 8.
Now price it. At a retail price of 16, pricing from the invoice tells you that you doubled your money: 8 becomes 16, a 100 per cent markup, a 50 per cent margin. Pricing from what you actually spent tells you the markup is about 51 per cent and the margin about 34 per cent.
Both calculations are arithmetically correct. Only one of them pays your rent. And the 16 per cent of revenue sitting between those two answers is not a rounding error, it is the difference between a product that funds the business and one that merely circulates money through it.
Those figures are illustrative rather than a benchmark. The point is the shape of the gap, not its size, and the shape is consistent: the lighter and cheaper the unit, the smaller the gap, and the heavier or more regulated it is, the larger.
What belongs in the number
The test is simple. Did you have to spend it to have one sellable unit sitting in your stockroom? If yes, it is in.
- Unit price from the supplier. The obvious one, and the only one most stores capture.
- Inbound freight. Sea, air or road, including any fuel surcharges, which move and are easy to forget because they arrive as an adjustment.
- Duty and tariffs. Driven by commodity code and country of origin, so two superficially similar products can carry very different rates.
- Customs brokerage and clearance fees. Usually a flat fee per shipment, which means it hurts small shipments far more per unit than large ones.
- Insurance on the shipment. Small, but real.
- Port, handling and demurrage charges. Demurrage in particular is the one that appears unexpectedly when a container sits longer than the free period.
- Inbound inspection and rework. If a percentage of every shipment arrives needing repackaging or relabelling, that is a cost of having sellable stock.
What does not belong: your own marketing, your payment processing fees, your pick and pack cost, your returns. Those are real costs of selling, and they matter enormously, but they are not the cost of having the unit. Mixing the two produces a number that cannot be used for either purchase decisions or pricing, because it moves when your ad spend moves.
The allocation problem nobody warns you about
Freight is charged per shipment and cost is needed per unit, so something has to divide one by the other. If the shipment contains one product, that is trivial. If it contains fourteen, it is a judgement call that materially changes which products look profitable.
Three ways to split it, in rough order of how much work they are:
- Evenly per unit. Divide total freight by total units. Fast, and fine when everything in the container is broadly similar in size and weight.
- By value. Allocate in proportion to each line's invoice value. Reasonable when you are shipping a mix of cheap and expensive items of similar bulk.
- By weight or volume. The accurate one, and the only one that works when you ship a heavy item alongside a light one. Freight is sold by space and mass, so this is the method that matches the way the cost was actually incurred.
The failure mode is specific and expensive: allocating evenly when you ship heavy and light goods together makes the light products look worse than they are and the heavy ones look better. Stores in that position have been known to discontinue their best-margin line because the spreadsheet said it was marginal.
Why it tends to be discovered late
The costs arrive separately and at different times, which is the entire reason this stays invisible. The supplier invoices you in week one. The freight forwarder invoices you in week five. Duty is paid by your broker and reconciled later. Handling charges appear on an account statement with a reference number nobody recognises.
By the time the full picture exists, the product has been priced, listed and sold for a month. Nothing forces a recalculation, because the pricing decision has already been made and nobody re-opens settled questions without a reason.
So the discipline is to estimate at purchase and reconcile at receipt. Estimate the landed cost before committing to the order, using your last comparable shipment as the basis. Then, when all the invoices for that shipment are in, go back and correct it. The estimate is what you price on; the reconciliation is what makes the next estimate better.
This is also an argument for recording the estimate next to the purchase order rather than in somebody's head, so the person doing the reconciliation six weeks later knows what was assumed and by whom. The purchase order process is the natural place for it, because that is already the document where the money gets committed.
Currency, which moves while you wait
If you buy in a currency you do not sell in, the rate on the day you paid is the rate that applies, not the rate when you ordered. On a long lead time that gap can be weeks, and the movement in between is a cost or a saving you did not decide on.
Two practical responses. Use the rate at payment for your actual landed cost, not the rate you assumed when ordering, because that is what left your account. And when estimating future orders, use a slightly conservative rate rather than today's, so the estimate degrades towards good news rather than bad.
None of this is sophisticated treasury management and it is not meant to be. It is just refusing to let an exchange rate quietly reprice your catalogue without anyone noticing.
Doing something with the number
Once you have a real landed cost per unit, three decisions get better, and they are not the decisions people expect.
Pricing, obviously. You can set a target margin and hit it, rather than aiming at a target you are measuring from the wrong baseline.
Minimum order quantities. Clearance fees and fixed handling charges are spread across the shipment, so a small order carries a much higher per-unit burden than a large one. That is a real argument for ordering more at once, and it is quantifiable rather than a feeling. It also explains why a supplier's minimum order quantity is sometimes doing you a favour.
Which products to drop. Fully costed, some products turn out to be busy rather than profitable. Those decisions are hard to make on instinct and straightforward to make on a number.
We built a landed cost calculator for the arithmetic. It takes unit price, freight, duty, insurance and handling, and tells you the per-unit cost and what your margin actually is at a given retail price. Nothing is stored and there is no signup, because it is a calculator rather than a lead magnet.
Where to start if you have never done this
Do not re-cost the catalogue. That is the project that gets abandoned in week two.
Take your five highest-volume products. For each, pull the last shipment and add up every invoice associated with it. Divide properly, by weight if the shipment was mixed. Compare the result to the cost you have been using.
Three things happen. Usually one product is much worse than you thought, which is immediately actionable. Usually one is better, which is a pricing opportunity rather than a problem. And you now know the rough percentage uplift between invoice and landed for your kind of goods, which lets you sanity-check the rest of the catalogue in an afternoon rather than re-costing it line by line.
That percentage is the real deliverable. It is a crude instrument and it is vastly better than the alternative, which is pricing everything from a number that was never the cost.
Common questions
What is landed cost, in one sentence?
Everything you spent to have one sellable unit in your stockroom: the supplier price plus freight, duty, clearance, insurance and handling, divided by the number of units.
Should marketing and payment fees be in it?
No. Those are costs of selling rather than costs of having stock. Including them produces a number that changes when your ad spend changes, which makes it useless for both pricing and purchasing decisions.
How should freight be split across a mixed shipment?
By weight or volume where the items differ in bulk, because that is how freight is actually charged. Splitting evenly across a shipment of heavy and light goods makes the light products look worse than they are.
What if duty and freight invoices arrive weeks apart?
Estimate at the point of ordering using your last comparable shipment, price on the estimate, then reconcile once every invoice for that shipment is in. The reconciliation is what makes the next estimate accurate.
Does this matter for a small store?
More, not less. Fixed charges like customs clearance are spread across the shipment, so smaller orders carry a higher per-unit burden, which means the gap between invoice price and true cost is widest for exactly the stores least likely to be measuring it.