Note: Information provided on this page is for general education only, please seek medical assistance when in doubt
Until about 20 weeks of pregnancy or in first half of pregnancy when the baby legs are curled up against their torso, length of babies are measured from the crown (top of the head) to the rump (or bottom). After 20 weeks the length of babies are measured from head to toe.
Growth of a baby inside the womb depends upon many factors such as genetics of their parents, age of the mother, number of children born to mother before this pregnancy, DNA of the child, nutrition and many other factors. The growth of babies inside the womb varies from woman to woman and pregnancy to pregnancy.
Though fertilization occurs in 3rd week, duration of the pregnancy is counted from the first day of your last menstrual cycle, so in
● In 1st week of your pregnancy the menstruation begins and ends towards the end of this week.
● In 2nd week of pregnancy, Ovulation occurs generally towards the end of this week and the released egg is now ready to be fertilized.
● After 2 weeks or in 3rd week of pregnancy, fertilization occurs in one of the fallopian tubes.
● After 3 weeks or in 4th week of pregnancy, fertilized egg known as a zygote is implanted in walls of uterus.
Below chart indicates the average fetal growth at the end of different weeks of pregnancy (Gestational age) and the below information is for reference only, From early in pregnancy, babies grow at different rates, growth of baby inside womb depends upon multiple factors and growth of your baby may differ slightly than indicated below, please consult your doctor whenever in doubt.
Length measured from Crown to Rump (CR)
| At End Of | Length (inches) |
Weight (ounces) |
Length (cm) |
Mass (gram) |
| 4 weeks | 0.1 inch | - | 0.25 cm | - |
| 5 weeks | ¼ inch | - | 0.4-0.6 cm | - |
| 6 weeks | ⅓ inch | - | 0.7-0.9 cm | - |
| 7 weeks | ½ inch | - | 0.8-1.1 cm | - |
| 8 weeks | ¾ inch | 0.04 ounce | 1.6 cm | 1 gram |
| 9 weeks | 0.90 inch | 0.07 ounce | 2.3 cm | 2 grams |
| 10 weeks | 1.22 inch | 0.14 ounce | 3.1 cm | 4 grams |
| 11 weeks | 1.61 inch | 0.25 ounce | 4.1 cm | 7 grams |
| 12 weeks | 2.13 inches | 0.49 ounce | 5.4 cm | 14 grams |
| 13 weeks | 2.91 inches | 0.81 ounce | 7.4 cm | 23 grams |
| 14 weeks | 3.42 inches | 1.52 ounce | 8.7 cm | 43 grams |
| 15 weeks | 3.98 inches | 2.47 ounces | 10.1 cm | 70 grams |
| 16 weeks | 4.57 inches | 3.53 ounces | 11.6 cm | 100 grams |
| 17 weeks | 5.12 inches | 4.94 ounces | 13 cm | 140 grams |
| 18 weeks | 5.59 inches | 6.70 ounces | 14.2 cm | 190 grams |
| 19 weeks | 6.02 inches | 8.47 ounces | 15.3 cm | 240 grams |
| 20 weeks | 6.46 inches | 10.58 ounces | 16.4 cm | 300 grams |
Length measured from Crown to Heel (after 20 week)
| At End Of | Length (inches) |
Weight (pound) |
Length (cm) |
Mass (gram) |
| 20 weeks | 10.08 inches | 10.58 ounces | 25.6 cm | 300 grams |
| 21 weeks | 10.51 inches | 12.70 ounces | 26.7 cm | 360 grams |
| 22 weeks | 10.94 inches | 15.17 ounces | 27.8 cm | 430 grams |
| 23 weeks | 11.38 inches | 1.10 pound | 28.9 cm | 501 grams |
| 24 weeks | 11.81 inches | 1.32 pound | 30 cm | 600 grams |
| 25 weeks | 13.62 inches | 1.46 pound | 34.6 cm | 660 grams |
| 26 weeks | 14.02 inches | 1.68 pound | 35.6 cm | 760 grams |
| 27 weeks | 14.41 inches | 1.93 pound | 36.6 cm | 875 grams |
| 28 weeks | 14.80 inches | 2.22 pounds | 37.6 cm | 1005 grams |
| 29 weeks | 15.2 inches | 2.54 pounds | 38.6 cm | 1153 grams |
| 30 weeks | 15.71 inches | 2.91 pounds | 39.9 cm | 1319 grams |
| 31 weeks | 16.18 inches | 3.31 pounds | 41.1 cm | 1502 grams |
| 32 weeks | 16.69 inches | 3.75 pounds | 42.4 cm | 1702 grams |
| 33 weeks | 17.20 inches | 4.23 pounds | 43.7 cm | 1918 grams |
| 34 weeks | 17.72 inches | 4.73 pounds | 45 cm | 2146 grams |
| 35 weeks | 18.19 inches | 5.25 pounds | 46.2 cm | 2383 grams |
| 36 weeks | 18.66 inches | 5.78 pounds | 47.4 cm | 2622 grams |
| 37 weeks | 19.13 inches | 6.30 pounds | 48.6 cm | 2859 grams |
| 38 weeks | 19.61 inches | 6.80 pounds | 49.8 cm | 3083 grams |
| 39 weeks | 19.96 inches | 7.25 pounds | 50.7 cm | 3288 grams |
| 40 weeks | 20.16 inches | 7.63 pounds | 51.2 cm | 3462 grams |
| 41 weeks | 20.35 inches | 7.93 pounds | 51.7 cm | 3597 grams |
| 42 weeks | 20.28 inches | 8.12 pounds | 51.5 cm | 3685 grams |
| 43 weeks | 20.20 inches | 8.19 pounds | 51.3 cm | 3717 grams |
Pregnancy is typically broken into three periods, or trimesters, each of about three months or about 14 weeks, resulting in a total duration of 42 weeks, although the average duration of pregnancy is actually about 40 weeks.
» First Trimester
» Second Trimester
» Third Trimester
| Fetal Growth in ... | |||
| 1st month | 2nd month | 3rd month | 4th month |
| 5th month | 6th month | 7th month | 8th month |
| 9th month | 10th month | ||