How long does it take sperm to die in air.

Minutes: Sperm is very sensitive to any environment other than testicles. Even in the vagina tons of sperm cells die quickly. Outside of the body it dies quickly as it dries up.

Since sperm: Generally don't fly through the air like birds, it's really hard to tell. If you mean how long do they live on a surface, they die as soon as they dry out. If you listen very, very closely you can often hear them crying out as they expire.