# How to Build a Landed Cost Model in a Spreadsheet That Survives a Tariff Change

Source: https://landedsight.com/blog/2026-11-15-landed-cost-model-spreadsheet-tariff-changes.html

Cross-border operations guide · November 15, 2026


**Short answer:** Build the model with one input cell per rate, so a tariff change means changing one cell, not rewriting the sheet. Stack the duties in separate columns, MFN plus Section 301 plus Section 232, so each rate is visible and each can change independently. Add scenario columns for freight up 30 percent and freight down 20 percent, and keep the exchange rate in a single cell that every formula references.

## One input cell per rate

The model that survives a tariff change is the model where a tariff change means changing one cell. Put every rate in its own input cell: the MFN rate, the Section 301 rate, the Section 232 rate, the merchandise processing fee at 0.3464 percent, the freight rate, the insurance rate, and the exchange rate. Every formula in the sheet references those cells, and no formula contains a hard-coded rate. When the rate changes, you change the cell, and the whole sheet recalculates. When the rate is hard-coded into twenty formulas, you change twenty formulas, and you will miss one.

The exchange rate gets the same treatment. Keep it in one cell, and have every formula that converts currency reference that cell. A model where the exchange rate appears in five different formulas at five different values is a model that is wrong in five different ways, and the errors do not cancel out.

## Stack the duties, do not blend them

Duty is not one number. It is a stack: the MFN rate, plus the Section 301 rate, plus the Section 232 rate, each applied to the customs value, each in its own column. A model that blends them into a single duty rate hides the structure, and the structure is what changes. Section 301 rates change by product and by exclusion. Section 232 rates changed in April 2026, from 25 and 10 percent to 50 percent on primary metals and 25 percent on derivatives. A model that shows the stack shows which rate moved and by how much. A model that shows a single blended rate shows only that the total moved, and leaves you guessing why.

The same logic applies to the other charges. Freight, insurance, port charges, broker fees, and financing each get their own column, so the model shows where the cost sits and which line moved when the total moves. A model that lumps freight and port charges into one line cannot tell you whether the freight went up or the port did, and the fix for a freight increase is different from the fix for a port increase.

## Scenario columns show the break before it happens

Add scenario columns next to the base case: freight up 30 percent, freight down 20 percent, duty up 10 points, and the exchange rate moved 5 percent in the wrong direction. The scenario columns are the model doing its job, which is to show you where the product stops making money before the market shows you. A product that makes money at base freight and loses money at freight up 30 percent is a product with a freight risk, and the risk is worth knowing before the freight actually goes up 30 percent.

Run the scenarios every time a rate changes, and run them before you commit to a purchase order, not after the goods are on the water. The model is a decision tool, not a record, and a model that is only updated after the fact is a diary, not a model. For the quote the model has to match, [brokerage fees and the landed cost they add](https://landedsight.com/blog/2026-11-14-brokerage-fees-landed-cost.md) covers the broker line, and [cargo insurance, CIF versus FOB](https://landedsight.com/blog/2026-11-14-cargo-insurance-cif-vs-fob.md) explains the insurance line that most models skip.

## Frequently asked questions

### How do I build a landed cost model in a spreadsheet?

Put every rate in its own input cell, so a tariff change means changing one cell. Stack the duties in separate columns, MFN plus Section 301 plus Section 232, and keep the exchange rate in a single cell that every formula references.

### What is landed cost?

The full cost of getting a product to your warehouse: product cost plus freight, insurance, duties, taxes, port and handling charges, broker fees, and financing, divided by the units. The per-unit number decides whether the product makes money.

### What is the merchandise processing fee?

The MPF runs 0.3464 percent of the customs value on a formal entry. It is a separate line in the model, not part of the duty rate, because it is calculated on the customs value and it changes independently.

### How do I model a tariff change?

Change the rate in its input cell and let the sheet recalculate. Add scenario columns for freight up 30 percent and down 20 percent, and for the duty up 10 points, so the model shows where the product stops making money before the market does.