How fast do fighter jets fly?

Front-line fighters reach maximum speeds of between Mach 1.6 and Mach 2.5. According to USAF fact sheets, the F-15 Eagle exceeds Mach 2.5 (over 3,000 km/h at high altitude) and the F-16 reaches Mach 2 (about 2,400 km/h). The Eurofighter Typhoon and the Rafale sit at Mach 2 and Mach 1.8 respectively, and the F-35, heavier and optimized for stealth, tops out at Mach 1.6 (about 1,950 km/h). These figures are measured at 11,000-12,000 m, where thin air allows maximum speed; at sea level the limit drops to about 1,400 km/h because of the dynamic pressure on the structure.

Maximum speed is almost never used. It requires afterburner, which multiplies fuel consumption by four or five and drains internal fuel in minutes, and external tanks and weapons lower the limit. In cruise, a fighter flies at 800-1,000 km/h (Mach 0.8-0.9), like an airliner, and in combat it maneuvers between 600 and 1,100 km/h, where turns are tighter. The short burst of acceleration into supersonic speed is reserved for launching a missile with extra energy or for escaping. Aircraft such as the Typhoon, the F-22 or the Rafale can also sustain supersonic flight without afterburner, so-called supercruise, around Mach 1.2-1.5.

The records are a thing of the past. The Soviet MiG-25 and the F-15 of the 1970s mark the peak of interceptors at Mach 2.5-2.8; since then designers have traded top speed for stealth, sensors and missile range. Today a fighter doesn't need to be the fastest, because its weapon, a Meteor or AMRAAM missile, flies at Mach 4 and decides the engagement dozens of kilometers away.