How are US import duties from Vietnam calculated?

Start with the base MFN rate for the HTS code, then stack the trade-remedy tariffs that apply to Vietnam. From Vietnam, the reciprocal baseline applies on top of the base MFN rate, plus Section 232 on metals. The China-specific Section 301 duties do not apply. The calculator does the stacking for your exact code and value.

Is there a free-trade agreement with Vietnam?

No US free-trade agreement applies to this origin, so the base MFN rate plus the reciprocal baseline tariff generally apply.

Vietnam import duties

Vietnam has become a major sourcing alternative to China, but it is not duty-free: the reciprocal baseline tariff applies, and Section 232 reaches Vietnamese steel, aluminum and copper articles. Vietnam is outside the Section 301 China actions, so the China-specific 301 duties do not apply.

Reciprocal baselineSection 232 (metals)