Formula Feeding Calculator: UK (NHS) & Australia Guide

How UK (NHS) and Australian Guidelines Work

The NHS recommends approximately 150–200 ml of formula per kilogram of body weight per 24 hours for full-term, healthy formula-fed babies. Most UK health visitors and midwives use the practical midpoint of 150 ml/kg/day — the same figure cited by the American Academy of Pediatrics (AAP), the CDC, and the WHO.

Australia's national infant feeding guidance, set out by the National Health and Medical Research Council (NHMRC) and published through healthdirect.gov.au, aligns with WHO recommendations: exclusive breastfeeding to six months is the first recommendation, and where formula is used, the weight-based calculation — approximately 150 ml/kg/day — is the standard reference for full-term babies. Australian formula brands follow the same principle, expressing it as age-based amounts on the tin because most parents know their baby's age more readily than their precise weight on any given day.

The upper end of the NHS range (200 ml/kg/day) is relevant primarily in clinical settings — for example, preterm babies in a neonatal unit who have higher energy needs per kilogram. For healthy term babies at home, the 150 ml/kg/day midpoint is the standard guide.

NHS Formula Feeding Calculator: How Much Formula for a UK Baby?

The NHS expresses formula amounts both by weight (150–200 ml/kg/day) and by age. The age-based figures assume an average growth trajectory; the weight-based calculation is more precise if your baby is above or below average for their age.

Here is how the 150 ml/kg/day rule translates at typical UK baby weights across the first six months:

• Newborn at days 10–14 (3.0–3.5 kg): 450–525 ml per day. Across 8 feeds: 56–66 ml per feed. Formula-fed newborns typically take 60–90 ml per bottle at this stage, consistent with this range.
• 4 weeks (3.5–4.0 kg): 525–600 ml per day. Across 6–8 feeds: 66–100 ml per feed. Most formula-fed babies at 4 weeks take 90–120 ml per bottle.
• 8 weeks (4.5–5.0 kg): 675–750 ml per day. Across 5–6 feeds: 113–150 ml per feed. The six-week growth spurt often increases demand briefly before settling back.
• 3 months (5.0–5.5 kg): 750–825 ml per day. Across 5–6 feeds: 125–165 ml per feed. Feeds are becoming more efficient; many UK babies settle into 5–6 bottles per day around this time.
• 4 months (5.5–6.5 kg): 825–975 ml per day. Across 5 feeds: 165–195 ml per feed. Formula intake approaches its practical daily ceiling; NHS guidance suggests not routinely exceeding around 900–950 ml per day to leave room for introducing solid foods at six months.
• 6 months (6.5–7.5 kg): Calculation gives 975–1,125 ml per day, but at this age solid foods begin alongside milk. UK and Australian guidelines recommend maintaining milk as the primary nutrition source while introducing solids gradually; total formula intake may stabilise or reduce slightly as the diet diversifies.

These figures are starting estimates. The NHS, AAP, and WHO all emphasise responsive feeding — watching hunger and fullness cues rather than pushing a baby to reach a specific ml target.

Australian Formula Feeding Guidelines

Australian health guidance on infant formula feeding is broadly consistent with the UK NHS approach and international WHO standards. Key points for Australian parents:

• Weight-based calculation: The same 150 ml/kg/day rule applies. Multiply your baby's current weight in kg by 150 to get the daily total in millilitres. Australian brands express this as age-based tin instructions, but the weight-based figure is more precise.
• Metric focus: Australian and UK feeding guidance is given entirely in millilitres — ounces are rarely used clinically in either country. The lookup table below gives ml amounts only.
• Brand guidance: Australian formula brands, including Aptamil Gold+ (Danone) and NAN Optipro (Nestlé), print age-based feeding tables on the tin. These tables are calibrated against average Australian growth data, which is closely aligned with WHO growth standards.
• Growth charts: Australian child health nurses use WHO growth charts (weight-for-age, length-for-age) to track progress. Consistent tracking along any growth percentile, combined with adequate wet nappies and settled behaviour, is the clearest evidence that formula intake is on track.

How Much Aptamil Should I Give My Baby?

Aptamil is one of the most widely used formula brands in both the UK (Aptamil First) and Australia (Aptamil Gold+). Both products follow their respective country's health authority guidelines, expressed as age-based amounts on the tin.

The on-tin Aptamil feeding guide typically looks like this at average baby weights:

• Birth to 2 weeks (approx. 3–3.5 kg): 60–90 ml per feed, 6–8 feeds per day. Daily total approximately 450–525 ml.
• 2–4 weeks (approx. 3.5–4 kg): 90–120 ml per feed, 6–7 feeds per day. Daily total approximately 540–720 ml.
• 1–2 months (approx. 4–5 kg): 120–150 ml per feed, 5–6 feeds per day. Daily total approximately 600–750 ml.
• 3–4 months (approx. 5–6 kg): 150–180 ml per feed, 5–6 feeds per day. Daily total approximately 750–900 ml.
• 5–6 months (approx. 6–7 kg): 180–210 ml per feed, 4–5 feeds per day. Daily total approximately 720–1,050 ml.

These are approximate ranges based on average UK and Australian weights. If your baby is heavier than average for their age, the age column on the tin may underestimate their needs — use the weight calculation instead. If your baby consistently drains every bottle and signals hunger again soon after, a modest increase per feed is a reasonable response.

Always follow the exact preparation instructions on the Aptamil tin. The scoop size and water-to-powder ratio are specific to each product and stage; using the wrong ratio can affect calorie and nutrient delivery.

How Much Lactogen Should I Give My Baby Per Day?

Lactogen is a Nestlé infant formula brand sold in a number of markets. Where Lactogen is available, its feeding instructions follow the local health authority's recommendations — which are in turn derived from the same WHO-aligned 150 ml/kg/day principle used by the NHS and NHMRC.

In markets where Nestlé sells NAN rather than Lactogen (including the UK and Australia), the NAN range carries the same weight-based guidance expressed as age-based amounts. Whether the tin says Lactogen, NAN, or another Nestlé variant, the underlying calculation is identical:

As with all brands, the on-tin preparation instructions define the correct scoop-to-water ratio. Never alter the concentration of made-up formula — too concentrated increases the salt and protein load on your baby's kidneys; too dilute delivers insufficient calories and nutrients.

Formula Feeding Lookup Table for UK and Australian Parents (3–7.5 kg)

The table below applies the 150 ml/kg/day rule across weights typical from birth to around 5–6 months. All amounts are in millilitres — the standard unit in UK and Australian clinical practice. Find your baby's current weight and use the column that best matches your daily feed count.

For babies feeding 5 times per day — common from around 3–4 months — divide the daily total by 5 to get the per-feed amount. For example, a 6 kg baby: 900 ÷ 5 = 180 ml per feed. For a weight not shown, multiply the exact weight in kg by 150 for the daily total, then divide by your daily feed count.

For an instant calculation, open the Baby Milk Calculator. Enter your baby's weight and daily feed count to get the per-feed amount in both ml and oz.

Signs Your Baby Is Getting Enough Formula

Whether you are following NHS, Australian, or WHO guidance, the signs of adequate intake are identical. The NHS, AAP, and WHO all agree that these observable markers are more meaningful than hitting an exact ml target:

• Wet nappies: At least 6 wet nappies per day from around day 5 onward is the most reliable hydration indicator at any age or weight. In the first few days, a simpler guide is one wet nappy per day of life (one on day one, two on day two, and so on up to day 5).
• Steady weight gain: Most babies gain 150–225 g per week in the first three months, slowing to roughly 85–140 g per week from three to six months. UK and Australian child health nurses use WHO growth charts; a baby tracking consistently along any percentile is almost certainly well nourished.
• Settles between feeds: A well-fed baby will typically relax, stop rooting, and have calm alert or sleep periods between feeds. Persistent unsettled behaviour after every feed warrants a call to your GP, health visitor, or child health nurse.
• Alert and engaged during wakeful periods: Good colour, responsive eyes, and age-appropriate muscle tone are reassuring signs of adequate nourishment.
• Fullness cues respected: A baby who consistently leaves formula in the bottle or turns their head away is signalling fullness. Responsive feeding — offering milk when hunger cues appear and stopping when fullness cues do — is recommended by both the NHS and Australian guidelines, as well as the AAP and WHO.

If wet nappy counts are consistently low, weight gain has stalled, or your baby seems lethargic and hard to rouse for feeds, contact your GP or health visitor (UK) or child health nurse (Australia) rather than independently adjusting formula volumes. Conversely, a baby who regularly drains every bottle and immediately signals hunger again may benefit from a modest increase in per-feed volume — particularly during a growth spurt.

The Bottom Line

Whether you are reading the NHS leaflet, the Aptamil tin, or an Australian healthdirect resource, the core calculation is the same: baby's weight in kg × 150 = daily formula total in ml. Divide by your daily feed count to get the per-feed amount. The lookup table above covers weights from 3 to 7.5 kg — from newborn through to the start of solids at six months — and all figures are in millilitres, matching UK and Australian clinical practice.

On-tin age-based guides from Aptamil, Lactogen, and other brands are a convenient shortcut derived from this same weight-based principle. They work well for average-weight babies; for babies who are noticeably heavier or lighter than average for their age, the weight calculation gives a more accurate starting target.

These figures are evidence-based starting points, not rigid targets. Consistent weight gain, adequate wet nappies, and a baby who settles between feeds are the real evidence that the amount is right. For personalised guidance, your GP, health visitor (UK), or child and family health nurse (Australia) is always the best resource.

For an instant weight-based calculation, open the Baby Milk Calculator or the focused formula calculator.