🍼 Baby Formula Calculator
Enter your baby's weight and age to estimate how much formula they need per day, how many ounces (mL) per bottle and how many feedings. General reference values.
How to use the formula calculator
Enter your baby's current weight (in pounds or kilograms) and choose their age. You'll get an estimated daily total, the amount per bottle in both ounces and milliliters, the number of feedings and how far apart they are. Feedings per day are set automatically by age, but if your baby eats more or fewer times, pick the real number — the daily total stays the same and is simply split differently. You can also change the amount per kilogram (150 mL/kg by default).
How much formula does a baby need?
Before solid foods (roughly the first 6 months), a common rule of thumb is about 150 mL per kg of body weight per day — about 2.3 oz per pound. The American Academy of Pediatrics' guide is similar: about 2½ ounces per pound per day (≈165 mL/kg). Babies vary from about 120 to 180 mL/kg, and the daily total doesn't keep rising with weight: most babies shouldn't need much more than 32 oz (about 1,000 mL) a day.
- Daily formula
weight (kg) × 150 mL, capped at 1,000 mL (32 oz). In pounds:weight (lb) × ~2.3–2.5 oz. - Per feeding
daily total ÷ feedings per day, rounded to 10 mL. - Interval
24 hours ÷ feedings per day, spread evenly including night feeds. - From 6 months solid food shares the calories, so the calculator shows typical ranges by age instead of the weight formula.
Example
A 2–3-month-old weighing 11 lb (5 kg): 5 × 150 = 750 mL (about 25 oz) a day. With 6 feedings that's 750 ÷ 6 = 125 mL — roughly 4 oz every 4 hours. With 5 feedings it's about 150 mL (5 oz) each. A 15½ lb (7 kg) baby would be 7 × 150 = 1,050 mL, so the 1,000 mL (32 oz) cap applies.
Formula amounts by age
| Age | Per feeding | Feedings/day | Per day (approx.) |
|---|---|---|---|
| 0–2 weeks | 60–90 mL (2–3 oz) | 7–8 | about 400–600 mL (14–20 oz) |
| 2–4 weeks | 90–120 mL (3–4.1 oz) | 6–8 | about 500–750 mL (17–25 oz) |
| 1–2 months | 120–160 mL (4.1–5.4 oz) | 6–7 | about 600–850 mL (20–29 oz) |
| 2–3 months | 140–180 mL (4.7–6.1 oz) | 5–6 | about 700–950 mL (24–32 oz) |
| 3–4 months | 160–200 mL (5.4–6.8 oz) | 5–6 | about 750–1,000 mL (25–34 oz) |
| 4–5 months | 180–220 mL (6.1–7.4 oz) | 5 | about 800–1,000 mL (27–34 oz) |
| 5–6 months | 200–220 mL (6.8–7.4 oz) | 4–5 | about 800–1,000 mL (27–34 oz) |
| 6–9 months (1–2 solid meals) | 180–220 mL (6.1–7.4 oz) | 3–4 | 600–800 mL (20–27 oz) + solids |
| 9–12 months (3 solid meals) | 180–240 mL (6.1–8.1 oz) | 2–3 | 500–700 mL (17–24 oz) + solids |
These are approximate ranges commonly seen on formula labels and in baby-care guides. Brands differ slightly in recommended amounts and feeding counts, so also check the feeding chart on your formula container. In the first few days after birth a newborn's stomach is tiny — they start with much less (often ½–1 oz per feeding) and build up day by day.
Watch your baby, not just the numbers
- Hunger cues Smacking or licking lips, sucking on hands, turning toward the bottle (rooting). Crying is often a late sign.
- Fullness cues Pushing the nipple away, turning the head, slowing down or falling asleep. There's no need to finish the bottle.
- Think in days It's normal for a baby to eat less at one feeding and more at the next. Look at the whole day, not a single bottle.
- Growth Steady weight gain on your pediatrician's growth chart and plenty of wet diapers (about 6 or more a day after the first week) matter more than any calculation.
Preparing formula safely
- Follow the water-to-powder ratio on the label exactly — never make it stronger or weaker.
- Throw away formula left in the bottle after a feeding; don't save it for the next one.
- Wash bottles and nipples thoroughly and follow the label for water temperature and storage.
This calculator gives approximate amounts based on commonly used guidelines. It is not medical advice. Every baby's needs differ, and premature babies, combination-fed babies and babies on special formulas may need different amounts. Follow your pediatrician's advice and the formula label, and talk to your pediatrician if you're worried about feeding or weight gain.