What age are men most fertile?

Although we haven’t yet pinpointed exactly what age men are most fertile, we know that male fertility decline typically begins at the age of 35 and gets steeper at 40.

The Centers for Disease Control and Prevention (CDC) reports that most men experience significant age-related fertility decline after they reach the age of 40. Other studies show that the decline begins around age 35—in one study, men over the age of 35 had fertility rates of 25%, compared to men under 35 who had fertility rates of 52%. Another study that evaluated the relationship between age and semen parameters also concluded that male fertility decline begins at 35, and suggested that male fertility peaks between 30 and 35.

Bottom line: Men generally see a decrease in fertility beginning at 35, and the decline progresses from there. The age men are most fertile may be between 30 and 35, but we haven’t yet determined a specific window of peak fertility.