How to Calculate a Baby's Weight

A baby's weight during pregnancy is not easily determined, but it is possible for professionals to give an approximate weight to expectant mothers based on the unborn baby's size and the size of the mother's stomach. After birth, it is much easier to weight an infant. This can be done using just a regular bathroom scale.

Instructions

In the Womb

1. Schedule an appointment to see your doctor or midwife.

2. Ask your midwife or doctor if they can determine your baby's size and approximate weight. They will typically make measurements of your stomach and uterus size to make these estimations.

3. Make a sizing ultrasound appointment. The ultrasound technician will measure your baby's size and use charts to determine the most common weight for a baby of that size.

Weighing a Baby at Home

1. Hold your newborn when he or she is wearing just a diaper or no clothes at all.

2. Step onto your bathroom scale and read the number it shows.

3. Place your infant into his or her crib and then step on your scale by yourself.

4. Subtract your weight from the number you saw when you were holding your baby. The resulting number is your infant's weight.

Tips & Warnings

• The most accurate weight reading for a young baby is taken in the pediatrician's office using a scale designed for babies.

References

• Kids Health: Growth and Your Newborn