If you can read this, you're old enough to masturbate! You may, though, be too young to ejaculate. Most boys begin to ejaculate semen when they're between the ages of 12 and 15, although some begin ejaculating at a later or earlier age. You can still masturbate and even have orgasms before you're old enough to ejaculate. However, for most males, the best-feeling orgasms are those that are accompanied by the ejaculation of a good amount of semen.