The US Air Force F-35 Has a J-20 Stealth Fighter Math Problem It Might Not Be Able to Solve

Estimates of China’s Chengdu J-20 fleet are closing in on the U.S. Air Force’s F-35A numbers, raising a “math problem” for analysts comparing airpower based on both capability and quantity. Expert Harrison Kass cites figures suggesting the PLAAF could have about 520 J-20s in service, nearing an estimated 550–580 F-35As delivered by July 2026. RUSI’s Justin Bronk counted 320–350 J-20s by end-2025 at roughly 120 per year, while Andreas Rupprecht’s tracking suggested near 500 by June 2026. The J-20 isn’t exported, so production feeds China’s domestic force exclusively.