How to calculate anti dumping duty: margin, cash deposit and landed cost

Last updated October 29, 2026·Data as-of: HTS 2026-10-19 / Section 301 2026-10-16 / AD-CVD 2026-10-16

The formula, and the three inputs it needs

Anti-dumping duty is an ad valorem charge assessed on the customs value of the merchandise, at the rate the order assigns to the producer or exporter. Written out, it is:

anti-dumping duty = customs value × (case margin ÷ 100)

Three inputs, and only one of them is arithmetic. The customs value is the entered value CBP assesses against — usually the transaction value, ex-factory, plus the international freight and insurance adjustments the entry declares. The case margin is the rate published in the order for that specific producer or exporter: a single order can carry a separate rate for each respondent, an “all others” rate for non-respondents, and a higher adverse-facts rate for parties that did not cooperate. The third input is scope: whether your product is described by the order at all. A product outside the scope owes nothing regardless of the margin.

Countervailing duty uses the identical formula with a different rate, and the two can stack. Of the 449 six-digit codes our AD/CVD dataset links to a case candidate, 151 carry both an anti-dumping and a countervailing candidate, which means the calculation for those codes is the sum of two multiplications, not one.

Worked example on a published margin

The margin below is not illustrative. It is the rate recorded in our AD/CVD dataset for case A-570-920 (China, Lightweight Thermal Paper From the People's Republic of China: Final…), published 2020-03-23 in Federal Register document 2020-06054. The table applies that margin to three order values, which is exactly what a broker does at entry time — the only difference is that the broker also has the producer-specific rate in front of them.

Anti-dumping duty on case A-570-920 at the published 115.29% margin.

Source: AD/CVD order dataset, case A-570-920 rate row (Federal Register 2020-06054) — https://www.federalregister.gov/documents/2020/03/23/2020-06054/lightweight-thermal-paper-from-the-peoples-republic-of-china-final-results-of-expedited-second (fetched 2026-10-16).

Two properties of that table are worth stating explicitly, because they are where importers mis-budget. First, the duty is proportional to value, so the percentage column never moves — the number that hurts is the absolute one, and it scales with the order rather than with the unit count. Second, this is a cash deposit, not a final assessment. The deposit is collected at entry and reconciled later in an administrative review; if the final rate comes out higher than the deposit, the difference is billed retroactively on every entry in the period of review.

The same multiplication at the top of the published range shows how far apart two cases can be. The highest rate in our dataset is 731.75% in case A-570-092, which on a $100,000 entry is $731,750 of anti-dumping duty alone — before the ordinary tariff, before countervailing duty if the order has one, and before the entry fees.^*

The same arithmetic at the top of the range (case A-570-092, 731.75%).

Source: AD/CVD order dataset, case A-570-092 rate row — https://www.federalregister.gov/documents/2025/02/06/2025-02299/mattresses-from-the-peoples-republic-of-china-final-results-of-expedited-sunset-review-of (fetched 2026-10-16).

Where a given margin sits in the distribution

Our dataset carries 896 rate rows across 555 cases, spanning 0% to 731.75% with a median of 24.29%. That spread is the reason a calculation example has to name its case: quoting “the anti-dumping rate” for a product is meaningless without the case number and the producer.^*

Distribution of the published margins in the AD/CVD dataset.

Source: AD/CVD order dataset, all rate rows with a numeric margin — https://www.federalregister.gov/documents/2020/03/23/2020-06054/lightweight-thermal-paper-from-the-peoples-republic-of-china-final-results-of-expedited-second (fetched 2026-10-16).

The bands are not evenly populated, and that shape is itself useful: a margin in the 25–50% band is unremarkable for a steel or chemical case, while a margin above 100% almost always signals an adverse-facts rate applied to a non-cooperating exporter. If your supplier's quoted rate looks extreme, check whether they were assigned the all-others rate or the adverse rate — the arithmetic does not change, but the number does.^*

Adding the rest of the stack

Anti-dumping duty is one line of a landed-cost build-up that has four more. The ordinary tariff comes first, at the general rate of the ten-digit line. Additional duties under Section 301 or Section 232 come next, and they apply independently of the AD/CVD order. Then the entry fees: the merchandise processing fee and, for ocean cargo, the harbour maintenance fee. Then the deposit itself.

The order matters for one reason: every ad valorem charge is computed on the same customs value, so an error in the declared value multiplies across all of them at once. A 10% understatement of value on an entry carrying a 25% general rate, a 25% Section 301 action and a 50% anti-dumping margin understates the total assessment by 10% of the sum, not by 10% of the duty line.

One more input sits outside the formula and changes the answer more than the formula does: the period of review. An order covers entries made in a defined window, and the deposit rate in force on the entry date is the rate that gets collected, even if the order is later amended. A shipment that enters three weeks before a preliminary determination is published deposits at the old rate; the same shipment three weeks later deposits at the new one. That is why a landed-cost model built on a single anti-dumping number goes stale silently — the arithmetic stays right while the input moves.

To run the full stack on a real code, the duty calculator applies the general rate and the entry fees, the AD/CVD case browser finds the case and margin for a code, and the stack exposure tool shows which codes carry both an anti-dumping and a countervailing candidate. The trade remedies index covers the order types, and the anti-dumping explainer covers the definitions this page assumes.^*

Three errors that change the answer

Using the country-wide rate for a producer-specific exporter. An order can publish a separate rate for each respondent. Applying the all-others rate to a producer that has its own rate over- or under-deposits on every entry, and the reconciliation at review settles it retroactively.

Assuming the deposit is the final duty. The deposit is an estimate collected at entry. The final liability is set in an administrative review of the period, and the difference is billed or refunded with interest.

Missing that the product is out of scope. Scope is the first question, not the last: a product whose description falls outside the order owes nothing, and importers who pay the deposit anyway can claim it back — but only if the entry was protested in time. The order types in our dataset (admin_review_results 1742, sunset_review_results 251, continuation 211) behave differently here, which is why the case number matters more than the product name.