How Much Formula?

Dear Lisa,

How much formula and how often should a 3 month, 13 pound baby drink? Thanks.

“How much formula?”

Dear “How much formula?”,

The amount of formula that an infant should take depends upon the weight of the child. A baby needs 50 calories per pound of body weight in a twenty-four hour period. (1)

Therefore a thirteen pound baby needs:

13 X 50 = 650 calories per day

Normal baby formula contains 20 calories per ounce. To figure out how many ounces a baby needs in one day, take the total calories required and divide by 20.

650 divided by 20 = 32.5 ounces of formula per day.

In general, most formula fed infants eat every 3 to 4 hours or 6 to 8 times per day. So in order to figure out how many ounces of formula are needed per feeding:

32.5 ounces divided by 6 = 5.4 ounces

32.5 ounces divided by 8 = 4 ounces

So your answer is:

A thirteen pound baby should drink 4 to 5 ½ ounces of formula per feeding.

This calculation does not apply to premature babies. If a baby is premature, the caloric requirements are different. In addition, premature babies many times are prescribed formulas that contain more then 20 calories per ounce.

It is a general belief that once a baby reaches 32 ounces per day, an increase in formula is not required. Instead, additional calories are given in the form of solid food fed to a baby by a spoon. A baby at three months old is too young to eat solid food. Solid food is typically introduced between the ages of 4 to 6 months old or when the infant doubles their birth weight. (2)

Besides reaching the age of 4 to 6 months, a child should be developmentally ready to accept the food. (2) An infant should have good head control and be able to sit up before he or she is allowed to eat solid food. (2) It is also important not to introduce solids before 4 months old because this may increase the risk of food allergies. A delay in the introduction of solid foods to an infant serves to reduce the risk of food allergies. (3)

Since your baby is already 13 pounds at 3 months old, it would be a good idea to discuss the proper time to introduce solids with your child's health care provider.

Congratulations on your new baby!

If you are interested in reading other Pediatric Advice stories discussing infant feeding issues:

Infant Feeding

Premature Infant Caloric Requirements

Nipple Confusion

Decreased Milk Production During Breastfeeding

Infant Colic

Gassy Baby

Introducing Cow’s Milk

Failure to Gain Weight

References:
(1) Chow M, Durand B, Feldman M, Mills M. Handbook of Pediatric Primary Care. Albany, New York:Delmar Publishers Inc. 1984: 303.
(2 )Grassia T. Pediatricians: Discuss healthy nutrition during well child checks. Infectious Diseases in Children. 2006. August: 54.
(3 )Bassett C. What to do when foods become allergens. The Clinical Advisor. 2005. Dec: 43-48.

Lisa-ann Kelly R.N., P.N.P.,C.
Certified Pediatric Nurse Practitioner

Pediatric Advice About Infant Care