Half marathon in 2:10: 9'55"/mile

1 track lap = 2'27"9

To run a half marathon in 2:10, hold 9'55" per mile, i.e. 6.05 mph (6'10"/km). At that pace: 5K in 30'49", 10K in 1h01'37", half marathon in 2h10'00", marathon in 4h20'00".