Section 301 tariffs don’t replace your normal duty rate, they stack on top of it. An importer who only budgets for the HTS duty rate and forgets Section 301 can be off by 25 percentage points or more on a China-origin shipment.
How Section 301 stacks with normal duty
Total duty = (Customs value × normal MFN rate) + (Customs value × Section 301 rate)
Both are calculated on the same customs value, and both get paid. A product with a 3% normal duty rate and a 25% Section 301 rate pays 28% total, not whichever number is larger.
Which rate applies to your product
Section 301 tariffs are assigned by specific HTS line, split across several “lists” published by USTR over multiple rounds, plus later product-specific actions (semiconductors, EVs, batteries, and others added at higher rates). There’s no single flat rate for “China imports” — you have to check your exact HTS code against the current USTR Section 301 action list.
The rate options in this calculator (7.5%, 25%, 50%, 100%) reflect the broad tiers that have applied to different product categories, but they move as USTR updates the list. Always verify your HTS code’s current status before filing, not from memory of last year’s rate.
Exclusions
USTR has periodically granted short-term exclusions for specific HTS codes, which pause the Section 301 tariff for that window. If your product category has ever had an exclusion, check whether it’s still active — these expire and get renewed (or don’t) on their own schedule, separate from the underlying tariff list.
Once you have your total duty number, run it through the landed cost calculator to see the full delivered cost per unit, or check MPF and HMF if you haven’t added those yet.