How Much Infant Formula Per Day? Calculator by Age and Weight
The pediatric gold standard is simple: 150 ml of formula per kilogram of body weight per day for infants aged 0–6 months. As the baby grows and starts solid foods (from 6 months), the rate drops to 110–120 ml/kg/day. Feeding frequency also changes with age: newborns feed 8 times a day, dropping to 5 by 6 months. This calculator combines both variables to give you the daily total and per-feeding volume instantly. Everything runs in your browser — no registration, no data stored.
Babies aged 0–6 months need approximately **150 ml of formula per kilogram of body weight per day**. A 6 kg, 3-month-old needs 900 ml/day split into 6 feedings of 150 ml each. After 6 months, when solids begin, this drops to 110–120 ml/kg/day. Total formula should generally not exceed 960 ml (32 oz) per day regardless of weight.
When to use this calculator
- Calculating the exact bottle size for a 3-month-old weighing 6 kg who feeds 6 times a day (150 ml per bottle)
- Determining whether a 5-month-old at 7.5 kg is getting enough formula before starting solid foods (target: ~960 ml/day max)
- Planning how many cans of powdered formula to buy per week based on daily ml totals for a 2-month-old
- Adjusting feeding volumes after a growth spurt when a baby's weight jumps between checkups
- Transitioning from 8 feedings/day as a newborn to 5 feedings/day at 6 months while keeping total daily intake appropriate
Example: 3-month-old, 6 kg
- Age: 3 months → 6 feedings/day
- Weight: 6 kg × 150 ml = 900 ml/day
- 900 ml ÷ 6 feedings = 150 ml per feeding
How it works
2 min readHow It's Calculated
The calculator uses the weight-based formula recommended by the American Academy of Pediatrics (AAP) and consistent with WHO infant nutrition guidance:
Daily ml = 150 ml/kg/day × Weight (kg) [ages 0–6 months]
Daily ml = 110–120 ml/kg/day × Weight (kg) [ages 6–12 months, with solids]
Feedings per day = age-based lookup (see table below)
ml per feeding = Daily ml ÷ Feedings per day> Hard cap: Total formula should generally not exceed 32 fl oz (≈ 960 ml) per day regardless of weight. Exceeding this can crowd out other nutrients and overload infant kidneys.
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Reference Table by Age and Weight
Values based on WHO 50th-percentile growth charts:
| Age | Typical weight | ml/kg/day | Feedings/day | ml per feeding |
|---|---|---|---|---|
| 1 month | 4.2 kg | 150 | 8 | ~79 ml |
| 2 months | 5.1 kg | 150 | 7 | ~109 ml |
| 3 months | 6.0 kg | 150 | 6 | 150 ml |
| 4 months | 6.7 kg | 150 | 6 | ~160 ml</td></tr><tr><th scope="row">5 months</th><td>7.3 kg</td><td>150</td><td>5</td><td>~192 ml |
| 6 months | 7.9 kg | 110–120 | 5 | ~192–230 ml</td></tr><tr><th scope="row">9 months</th><td>9.2 kg</td><td>110–120</td><td>4–5</td><td>~200–240 ml |
| 12 months | 10.0 kg | 100–110 | 3–4 | ~200–280 ml* |
*Capped at 960 ml/day total; excess calories covered by complementary foods.
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Worked Examples
Case 1 — 1-month-old, 4 kg
Case 2 — 3-month-old, 6 kg (the classic case)
Case 3 — 5-month-old, 7.5 kg
Case 4 — 8-month-old, 8.5 kg (eating some solids)
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Common Mistakes
1. Ignoring the 960 ml (32 oz) daily cap — Heavier babies may calculate over 960 ml, but exceeding this limit can cause overfeeding and iron overload from fortified formula.
2. Using volume, not weight, to gauge hunger — Formula intake should be weight-driven, not based on finishing the bottle. Forcing a baby to finish a bottle overrides hunger cues.
3. Not adjusting downward after solids begin at 6 months — Continuing 150 ml/kg after solid foods are introduced leads to excess caloric intake. Switch to the 110–120 ml/kg/day rate.
4. Preparing bottles with incorrect water-to-powder ratios — Standard powder formula is mixed at 1 scoop per 2 fl oz (60 ml) of water. Diluting too much reduces caloric density; over-concentrating stresses infant kidneys.
5. Skipping nighttime feedings in the total count — Especially for 0–2 month infants who feed every 2–3 hours around the clock, night feeds must be included in the daily total.
Frequently asked questions
How many ml of formula does a newborn need per day?
Newborns typically need about 150 ml per kilogram of body weight per day. A 3.5 kg newborn needs roughly 525 ml spread over 8–10 feedings, working out to about 55–65 ml per bottle. Volume increases steadily over the first weeks as the stomach grows. By 1 month, most babies take 75–90 ml per feeding 8 times a day.
How much formula does a 3-month-old need?
A 3-month-old at average weight (6 kg) needs 6 × 150 = 900 ml/day in 6 feedings of 150 ml each. If your baby weighs more or less, multiply their weight in kg by 150 to get the correct daily total.
How many ml of formula for a 2-month-old?
A 2-month-old typically weighs around 5 kg: 5 × 150 = 750 ml/day across 7 feedings = ~107 ml per feeding. Many parents round to 120 ml per bottle and let the baby stop when satisfied.
Is there a maximum amount of formula a baby should have per day?
Yes. The general pediatric guideline is a hard cap of 32 fl oz (approximately 960 ml) per day for infants, regardless of body weight. Exceeding this can crowd out nutrients from other foods, contribute to obesity risk, and overload the kidneys with protein and minerals.
When should I start reducing formula amounts?
Formula volumes should taper after 6 months once solid foods are introduced. The AAP recommends maintaining formula as the primary nutrition source for the first 12 months, but reducing from ~150 ml/kg/day to 110–120 ml/kg/day as iron-rich solids contribute more calories. Never replace formula with cow's milk before 12 months.
How do I know if my baby is getting enough formula?
Key signs of adequate intake: 6 or more wet diapers per day, steady weight gain of roughly 150–200 g/week in the first 3 months (per WHO/CDC growth charts), and a baby who seems satisfied after feeds. Weight checks at well-child visits help confirm adequate intake.
How much formula does a 4-month-old need at each feeding?
At 4 months, most babies weigh between 6–7 kg and feed about 6 times per day. Using 150 ml/kg: a 6.5 kg baby needs ~975 ml/day, capped at 960 ml, divided by 6 feedings = about 160 ml per bottle. Always watch hunger and fullness cues rather than insisting the baby finish a set amount.
Can I use this calculator for premature babies?
Premature infants have different caloric and volume requirements — often 160–180 ml/kg/day — and may require fortified or specialty formulas. Their intake should be managed using their corrected gestational age, not chronological age. This calculator is designed for full-term infants; always follow NICU discharge instructions and neonatologist guidance for preemies.
How many cans of powdered formula will I need per week?
A standard 12.4 oz (351 g) can of powdered formula typically makes about 87 fl oz (≈ 2,570 ml) of prepared formula when mixed at 1 scoop per 2 oz water. If your baby drinks 900 ml/day (≈ 30 fl oz/day), you'll use about 210 fl oz per week — roughly 2.4 cans per week. Larger 32 oz cans yield about 225 fl oz, so approximately one large can per week.
Does the formula brand affect how many ml I should give?
Most standard infant formulas provide 20 kcal per fl oz (67 kcal/100 ml) when mixed correctly, so volume targets remain the same across brands. High-calorie formulas (22 or 24 kcal/fl oz) are sometimes prescribed for premature or failure-to-thrive infants — in those cases, your pediatrician will adjust volume targets specifically.