// Free tool · v0.1 · No account · Browser-only

OFAC 50-Percent Rule Calculator

Paste a multi-tier corporate ownership chain. The tool computes aggregate ownership held by sanctioned persons for every non-SDN entity and flags any whose share held (directly or indirectly) by SDN persons is 50% or more — the threshold at which an entity is itself blocked under OFAC FAQ 401. All computation runs in your browser. Nothing is sent to a server, nothing is stored.

One row per ownership link. Columns: owner_name, owned_entity, percent, is_sdn (true/false). Header row optional. Comma-separated. Quote names containing commas.

// Scope & limits This calculator implements the OFAC 50-Percent Rule mechanically. It does not handle control-based blocking (post-GVA Capital 2025 expansion of the test beyond pure ownership), trust structures, beneficial-ownership constructive holdings via nominees, or EU-equivalent ownership-or-control test variations under EU Council Regulation 269/2014. Output is a starting point for compliance review, not a legal determination. See our OFAC 50-Percent Rule methodology explainer for full nuance and the case-law that has moved the test.

OFAC source guidance

  • FAQ 398 — What does “owned” mean for purposes of the 50-Percent Rule?
  • FAQ 399 — Aggregation across multiple SDN owners.
  • FAQ 400 — Indirect ownership through intermediate entities.
  • FAQ 401 — The 50-percent threshold and automatic blocked-property status.
  • FAQ 402 — Control vs. ownership; separate analysis for control-based blocking.

How the aggregate ownership algorithm works

  1. Parse the input into directed ownership edges (owner → target, percent, owner_is_sdn).
  2. Cycle check. Build the ownership graph and run a depth-first traversal. If any cycle is detected (e.g. A owns B owns C owns A), refuse to compute and report the cycle — the recursion is mathematically undefined and the chain likely contains a data error.
  3. Recursive aggregation. For each non-SDN entity, sum the share held by SDNs:
    • Direct SDN owner contributes its full percent.
    • For each non-SDN intermediate owner, first compute its own sanctioned aggregate. If that aggregate is ≥ 50%, the intermediate is itself blocked — its FULL percent passes through to the downstream entity. If < 50%, only a fractional share passes through (intermediate’s aggregate × its percent ÷ 100).
  4. Flag any entity whose total sanctioned aggregate is ≥ 50% as BLOCKED.
  5. Trace. For each entity, the “Why” expander reconstructs the contributing owners, the propagation type (direct SDN / fully-blocked intermediate / partial pass-through), and the resulting per-edge contribution.

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