Average Sperm Production in Men
A lot of sperm - that's what the average, healthy man makes each second. Researchers have estimated that men's bodies make 1,500 sperm per second - or, to put it in a fancy, eye-catching way - per heartbeat.
"Men have the overwhelming quantitative edge in the gamete games. Whereas current evidence suggests that a human female is born with all the eggs she will have, and that only about 500 of her natal stock of one million will ever ripen and have a shot at fertilization, a male from puberty onward is pretty much a nonstop sperm bakery. Each testicle generates more than 4 million new sperm per hour, for a lifetime total of maybe 12 trillion sperm per man (although the numbers vary with the day and generally slope downward with age)." (nytimes.com
More about sperm
A Walk Through Reproduction from a Sperm's Point of View