How long does it take sperm to die after expulsion?

Depends where: Sperm can live up to a week in the fallopian tube if they get that far. Do not survive more than a few hours in vagina unless they pass thru opening in cervix. They need to pass thru uterus to fallopian tube to survive. Die soon after ejaculation if outside vagina. Can survive many years if frozen as at a sperm bank. Need to be inserted rapidly after ejaculation if used for artificial insemination.