Build a landed cost estimate before you ask for a quote.

What this estimate includes

Four inputs and one arithmetic rule. Goods value plus freight gives the figure duty is charged on; the duty rate you enter is applied to that combined figure rather than to the goods alone, which is how most destinations assess it on a CIF basis. Other costs are added flat, and the unit figure is the total divided by your quantity. That is the whole model — there is nothing hidden in it, which is also why it cannot be the number you commit to.

• Duty is calculated on goods plus freight, not on goods alone
• Other costs are added as a flat sum, not spread or scaled
• The unit figure is the total divided by the quantity you entered

What it leaves out, and why that matters

It does not know your Incoterm, your product's classification, your destination's tax treatment, or any trade measure that applies to your specific goods. Those are exactly the variables that move a landed cost most, and none of them can be inferred from four numbers. Treat the output as a way to see which input dominates your cost, not as a quotation.

• No HS classification, and therefore no verified duty rate — the rate is the one you typed
• No import VAT, GST or sales tax, which in several markets exceeds the duty
• No antidumping, countervailing or other trade-remedy duty
• No customs brokerage, port, demurrage, storage or last-mile delivery charges
• No currency movement between quotation and payment

Where the inputs should come from

The quality of the answer is set entirely by the quality of the four numbers. Goods value should be the factory's price for the quantity you are actually buying, not a sample-quantity price. Freight should be a forwarder's quote against your real carton dimensions and weights, not a rule of thumb. The duty rate should come from your customs broker against a classification they are willing to stand behind — and a rate you guessed is a rate the total inherits.

• Factory price at your real order quantity, on a stated Incoterm
• Freight quoted against verified carton counts, dimensions and weights
• A duty rate your broker gave you against a specific classification

What we can and cannot help with here

Two of the three inputs are things a check can make real. Verified carton counts, dimensions and weights come out of a pre-shipment inspection rather than out of the supplier's estimate, and a supplier verification tells you whether the party quoting the goods price is the party that makes them. The third input is not ours: we do not classify goods, and we do not advise on duty or tax. That question belongs with your customs broker.