Duty = Dutiable Value × Duty Rate, plus statutory fees on top. This article helps you estimate US import duty line by line.
First, Calculate the Dutiable Value
The dutiable value is the base customs uses to assess duty. It is not your retail price.
US imports are usually based on the transaction value of the goods, meaning the value actually paid or payable.
It generally excludes international freight and insurance, which are listed separately elsewhere.
Declared value must be truthful: declare too low and it will be questioned; declare too high and you pay more duty.
Then Check the Duty Rate: The HTS Code Decides Everything
Every product category corresponds to an HTS code, the Harmonized Tariff Schedule code of the United States.
Once the code is found, the corresponding duty rate is the assessment percentage.
For the same product, different material or use can mean a completely different code and duty rate.
Some countries also face additional tariffs on specific categories.
The Main Formula and Variables
| Variable | Meaning | How to Determine |
|---|---|---|
| Dutiable Value | Assessment base | Based on transaction value, adjusted per customs rules |
| Duty Rate | Rate corresponding to the HTS code | Look up the rate published by US Customs by code |
| Duty | Duty payable | Dutiable Value × Duty Rate |
| Additional Fees | Statutory fees such as MPF and HMF | Calculated at the statutory rates published by US Customs |
| Total Payable | Total import-related taxes and fees | Duty + all additional fees |
Duty = Dutiable Value × Duty Rate
Total Payable = Duty + MPF + HMF (if applicable)
MPF is generally charged at a statutory percentage of the goods value with a floor and ceiling, and HMF applies only to ocean imports. The percentages and floor/ceiling are subject to what US Customs publishes.
Step-by-Step Estimate for You
Example: one shipment of 200 cartons, total declared value USD 10,000, imported by ocean.
Step 1, set the dutiable value: USD 10,000.
Step 2, look up the HTS code to determine the duty rate. Assume 5%; this figure is for illustration only, and the actual rate follows the code.
Step 3, calculate duty: 10,000 × 5% = USD 500.
Step 4, add MPF: multiply the goods value by the statutory percentage, subject to the floor and ceiling.
Step 5, add HMF: charged at the statutory percentage of the ocean freight value.
The sum of the three is the total payable. The actual amount is affected by the duty rate, goods value and exchange rate, and is subject to live quotations.
Should the Quote Include Freight and Insurance
US imports are based on transaction value, and freight and insurance are usually not included in the dutiable value.
If the transaction value already includes freight and insurance, they must be deducted per the rules.
If the paperwork is filled in wrong, you will be asked to correct it during customs clearance, and the cargo will be stuck at the port.
Is There Any Duty-Free Room for Low-Value Goods
The US low-value duty exemption (USD 800) has been tightened: the exemption for most countries was removed from August 2025, and from June 2026 the exemption for goods valued at USD 800 or less via non-postal channels is suspended indefinitely, requiring formal or informal entry (subject to the latest official announcement from US Customs).
This is a rule for personal-use scenarios and does not apply to commercial imports.
Do not split commercial goods into personal parcels to force them under the threshold.
How to Estimate Duty More Accurately
Write the product name specifically: "plastic storage box" is easier to classify correctly than "household goods".
Write material, use and function in full; these three are key to classification.
For mixed loads of multiple categories, declare by category separately, not as one lump-sum price.
Keep purchase contracts and invoices as support for the dutiable value.
Two Common Misconceptions
Misconception 1: Duty is a fixed few percent. Duty rates vary widely between different HTS codes.
Misconception 2: Under-declaring value saves money. If found out, you must pay back duty plus penalties, costing far more than the duty itself.
