How do you calculate a horses age?

This is a very interesting question. A horse's ACTUAL age is his age from the day he was born. HOWEVER, for Thoroughbred RACING purposes, all Thoroughbreds become one year older on January 1 of each year, regardless of when they were actually born.

So a horse born on February 6, 2007, and a horse born on April 30, 2007 BOTH become ONE YEAR OLD on January 1, 2008. On January 1 and thereafter they will be the same age for racing purposes, even though they were born almost 3 months apart.

I hope that answers your question.