Mean Sac Diameter Calculator

Free calculate gestational age from mean sac diameter (MSD). This is an educational tool only - always consult a healthcare provider.

Gestational Sac Measurements

Results

Enter measurements to calculate mean sac diameter

About Mean Sac Diameter

  • • MSD = (Length + Width + Height) / 3
  • • Gestational Age (days) = MSD + 30
  • • Used in early pregnancy (before fetal pole visible)
  • • Typically measured at 5-7 weeks gestation
  • • More accurate after 6 weeks with CRL