This calculator gives general estimates for information only. It does not replace advice from your doctor, pharmacist or another qualified health professional.
How much formula does a baby need?
Formula-fed babies regulate their intake well when they are fed on cue, so the amounts below are a guide, not a target to reach at every feeding. The most common rule of thumb in the US, given by the American Academy of Pediatrics, is about 2.5 fluid ounces of formula per pound of body weight per day, without going over 32 ounces a day. Pediatric nutrition texts often state it as 150 mL per kilogram per day, which is almost the same.
The formulas
- Formula per day = 2.5 fl oz × weight in lb, up to 32 fl oz
- Per bottle = daily amount ÷ number of feedings
- Scoops = ounces of water ÷ 2, for formulas that use one unpacked scoop per 2 fl oz of water (check your can: some brands differ)
Worked example: an 11 lb baby, 6 feedings a day
- Per day: 2.5 × 11 = 27.5 fl oz (813 mL).
- Per bottle: 27.5 ÷ 6 = 4.6 fl oz, so a 4.5 to 5 oz bottle.
- Powder: 4.6 ÷ 2 = about 2.3 scoops. In practice, prepare 4 oz of water with 2 scoops, or 6 oz with 3, and let the baby stop when full.
- The 150 mL/kg rule gives 748 mL (25.3 fl oz): the two estimates bracket a normal intake.
Daily amount by weight
| Weight | Per day | Per bottle (6 a day) |
|---|---|---|
| 7 lb | 17.5 fl oz | 2.9 fl oz |
| 9 lb | 22.5 fl oz | 3.8 fl oz |
| 11 lb | 27.5 fl oz | 4.6 fl oz |
| 13 lb | 32 fl oz (max) | 5.3 fl oz |
| 15 lb | 32 fl oz (max) | 5.3 fl oz |
Typical number of feedings
- Newborn: 8 to 12 feedings in 24 hours, 1 to 3 oz each in the first weeks.
- 1 to 2 months: 6 to 8 feedings of 4 to 5 oz.
- 4 to 6 months: 4 to 6 feedings of 6 to 8 oz.
- From about 6 months, solid foods start and formula gradually decreases, to around 24 oz a day by the first birthday.
Signs the amount is right
- Six or more wet diapers a day after the first week.
- Steady weight gain on the growth chart at check-ups.
- The baby seems satisfied after feeding and turns away from the bottle when full.
Safe preparation
Always add water first, then the scoops, leveled without packing. Too much powder can dehydrate a baby and too little can starve them, so never change the ratio. Use prepared bottles within 2 hours (1 hour once feeding starts), and throw away what is left. Ask your pediatrician if your baby was premature, has reflux or does not gain weight as expected.