Market Data

Effective vs Statutory Tariff Rates: Why the Schedule Isn't What You Pay

The tariff schedule's printed rate and the duty bill that clears customs are different numbers. Understanding the gap is the difference between a quote that holds and one that doesn't.

Ask the Harmonized Tariff Schedule what a steel bolt pays at the border and it gives a tidy answer: the MFN column for heading 7318 runs Free–12.5%. Ask the customs data what importers actually paid and the answer is very different: 35.91% of customs value in 2025. The gap between those two numbers, the statutory rate and the effective rate, is where Section 301 lists, Section 232 metals actions, exclusions, and trade-program preferences all live, and it is the number that belongs in a landed-cost model.

• Statutory MFN, fasteners (HTS 2026): Free–12.5%
• Effective rate paid, 2025: 35.91%
• Change vs 2024: +29.4 points

The effective rate is empirical: calculated duties actually collected divided by the customs value of imports for consumption, from USITC DataWeb. It needs no model of which overlay applies to which line, because it simply measures the outcome. Across the 57 manufacturing import families MFG Calcs tracks, importers paid an average effective rate of 12.4% of customs value in 2025, versus 3.3% the year before.

The statutory column tells you the floor. The effective rate tells you the market. Quote from the second, verify against the first.

How to use each number

• Statutory MFN: the baseline for duty drawback math, FTA qualification analysis, and any entry where no overlay applies.
• Effective rate: the realistic planning number for a category, especially where Section 301/232 overlays dominate.
• Per-country effective rates: the sourcing comparison: the same bolt can carry a single-digit rate from one origin and a punitive one from another.

Every family page in the MFG Calcs Tariff Monitor shows both columns side by side with top source countries, and the numbers refresh automatically as USITC publishes. Reference statistics derived from USITC published data. Not a customs ruling; verify rates with a licensed customs broker before relying on them.

Statutory and effective rates for 57 manufacturing families, with source-country breakdowns. Look up your product family

Published 2026-07-19.