4'20"/km = 13.85 km/h · 8.60 mph

1 track lap = 1'44"0

At 4'20" per kilometre you run 13.85 km/h, or 8.60 mph (6'58"/mile). 5K in 21'40", 10K in 43'20", half marathon in 1h31'25", marathon in 3h02'51".