Pregnancy Pregnancy Development Stages Fetal Development How Big Is Your Baby in Third Trimester? Wonder how big your baby is now? Here's an approximate look at size, weight and height in the third trimester. By Parents Editors Published on May 16, 2006 Share Tweet Pin Email Trending Videos 01 of 12 Week 28 Warren Millar - Fotolia.com Baby's Length: 15.25-15.75 in. Baby's Weight: 2.25-2.5 lbs. Baby's Size: Pair of sneakers All length measurements in the third trimester are now full-length (instead of just head-to-butt), because your baby's big enough to describe them more accurately! Free Weekly Ages & Stages Newsletter! Free Daily Kick Pregnancy Newsletter! 02 of 12 Week 29 Baby's Length: 15.75-16.25 in. Baby's Weight: 2.5-2.75 lbs. Baby's Size: Basketball Free Weekly Ages & Stages Newsletter! Free Daily Kick Pregnancy Newsletter! 03 of 12 Week 30 Anton Gvozdikov - Fotolia.com Baby's Length: 16.25-17 in. Baby's Weight: 3 lbs. Baby's Size: Thick Wool Sweater, Folded Free Weekly Ages & Stages Newsletter! Free Daily Kick Pregnancy Newsletter! 04 of 12 Week 31 John Steel - Fotolia.com Baby's Length: 17-18 in. Baby's Weight: 3.5 lbs. Baby's Size: Soccer ball Free Weekly Ages & Stages Newsletter! Free Daily Kick Pregnancy Newsletter! 05 of 12 Week 32 Michael Rí¶hrich - Fotolia.com Baby's Length: 18-19 in. Baby's Weight: 4 lb. Baby's Size: 5-lb. bag of potatoes Free Weekly Ages & Stages Newsletter! Free Daily Kick Pregnancy Newsletter! 06 of 12 Week 33 James Cox - Fotolia.com Baby's Length: 19-19.5 in. Baby's Weight: 4.5 lbs. Baby?s Size: Medicine ball Free Weekly Ages & Stages Newsletter! Free Daily Kick Pregnancy Newsletter! 07 of 12 Week 34 Baby's Length: 19.5-20 in. Baby's Weight: 5 lbs. Baby's Size: Medium pumpkin Free Weekly Ages & Stages Newsletter! Free Daily Kick Pregnancy Newsletter! 08 of 12 Week 35 Baby's Length: 20-20.5 in. Baby's Weight: 5.5 lbs. Baby's Size: Throw pillow Free Weekly Ages & Stages Newsletter! Free Daily Kick Pregnancy Newsletter! 09 of 12 Week 36 Baby's Length: 20.25-20.75 in. Baby's Weight: 6 lbs. Baby's Size: Beach ball Free Weekly Ages & Stages Newsletter! Free Daily Kick Pregnancy Newsletter! 10 of 12 Week 37 Baby's Length: 20.75-21 in. Baby's Weight: 6.5 lbs. Baby's Size: Diaper bag Free Weekly Ages & Stages Newsletter! Free Daily Kick Pregnancy Newsletter! 11 of 12 Week 38 Baby's Length: 21-21.5 in. Baby's Weight: 6.5-7 lbs. Baby's Size: Watermelon Free Weekly Ages & Stages Newsletter! Free Daily Kick Pregnancy Newsletter! 12 of 12 Week 39 Veer Images Baby's Length: 21.5 in. Baby's Weight: 7-7.5 lbs. Baby's Size: Newborn All content on this Web site, including medical opinion and any other health-related information, is for informational purposes only and should not be considered to be a specific diagnosis or treatment plan for any individual situation. Use of this site and the information contained herein does not create a doctor-patient relationship. Always seek the direct advice of your own doctor in connection with any questions or issues you may have regarding your own health or the health of others. Free Weekly Ages & Stages Newsletter! Free Daily Kick Pregnancy Newsletter! Was this page helpful? Thanks for your feedback! Tell us why! Other Submit