It typically takes about 24 to 48 hours for sperm levels to return to baseline after ejaculation, meaning the body replenishes sperm to the usual count within this timeframe. However, achieving optimal sperm quality and quantity may take several days to weeks. The entire sperm production and maturation cycle (spermatogenesis) takes around 64 to 74 days, but partial replenishment of sperm count begins immediately after ejaculation and reaches baseline within 1 to 2 days.

Key Details:

• After ejaculation, sperm production continues, but fully mature sperm take longer to regenerate.
• Sperm count returns to baseline roughly 24 to 48 hours after ejaculation, supporting the possibility of multiple ejaculations in a short period with some reduction in quality and quantity.
• Full sperm regeneration, including the process of developing and maturing sperm, takes about 64 days plus 10-14 days for maturation in the epididymis (total around 74 days).
• Factors like hydration, diet, overall health, exercise, alcohol, smoking, and stress influence sperm replenishment and quality.

In summary, sperm levels "build back up" to typical levels within 1 to 2 days after ejaculation, but complete new sperm production takes about two and a half months.