The largest US defense contractors can be ranked by revenue, backlog, Pentagon contract obligations or total federal awards. Those measures overlap, but they are not identical. A multiyear aircraft or missile contract can generate a large federal obligation before all of the associated company revenue is recognised.
ACR uses USAspending and Department of Defense contract releases to anchor the public-spending side of the comparison, then company filings for backlog and segment economics.
A small group of primes dominates complex programmes
Lockheed Martin, RTX, General Dynamics, Northrop Grumman and Boeing operate across aircraft, missiles, sensors, space, shipbuilding and classified programmes. Their scale comes partly from the technical and regulatory barriers around national-security procurement.
Large primes also sit above thousands of suppliers, meaning the economic footprint of one contract can spread across many states and smaller companies.
Backlog matters as much as one year's awards
Defense programmes often run for years or decades. A company's backlog can therefore give a better view of future work than one quarter of new awards.
Investors still need to distinguish funded backlog, options, indefinite-delivery vehicles and headline programme values. Not every announced ceiling becomes revenue.
Federal data make the cluster updateable
USAspending allows award activity to be followed by recipient, agency and geography. That makes this page suitable for regular refreshes without relying on opaque third-party rankings.
ACR will use that source base to connect contractor scale with state-level aerospace and defense clusters already covered elsewhere on the site.