Baby Formula Calculator: UK (NHS) & Australia Guide

How UK (NHS) and Australian Guidelines Work

NHS 111 Wales says that by the end of the first week most babies need roughly 150–200 ml of formula per kilogram of body weight per 24 hours until around 6 months. It also stresses that babies vary and should be fed responsively.

Australian Government-backed Pregnancy, Birth and Baby guidance is more age-specific: 30–60 ml/kg/day at 1–4 days, 150 ml/kg/day from 5 days to 3 months, 120 ml/kg/day from 3–6 months, and 100 ml/kg/day from 6–12 months.

These are planning guides, not prescribed bottle sizes. The baby's hunger and fullness cues, growth, wet nappies, and clinical advice matter more than reaching an exact total.

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

The NHS 150–200 ml/kg/day figure is a broad range from the end of the first week, not a precise prescription. For example:

• 3.5 kg: roughly 525–700 ml across 24 hours.
• 4 kg: roughly 600–800 ml across 24 hours.
• 5 kg: roughly 750–1,000 ml across 24 hours.

Divide the daily range by the number of feeds only to estimate bottle size. Do not push a baby to finish the result; the NHS advises feeding when hunger cues appear and stopping when the baby is full.

Australian Formula Feeding Guidelines

Pregnancy, Birth and Baby publishes this age-based guide for formula intake:

• 1–4 days: 30–60 ml/kg/day.
• 5 days–3 months: 150 ml/kg/day.
• 3–6 months: 120 ml/kg/day.
• 6–12 months: 100 ml/kg/day.

These rates explain why one fixed 150 ml/kg calculation should not be applied across the whole first year. Use the current age, then follow the exact preparation directions on the formula tin.

How Much Aptamil Should I Give My Baby?

Aptamil products and stages can have different feeding tables and preparation ratios. Use the guide printed on the exact tin you are preparing, and check that the product is suitable for your baby's age.

The calculator on this site can provide a rough intake sense-check from weight and age, but it does not calculate powder scoops. Never substitute its result for Aptamil's water-to-powder instructions or use a scoop from another tin.

Cow & Gate, Kendamil & SMA: Other UK On-Tin Guides

UK first infant formulas must meet compositional and labelling requirements, but that does not make every feeding table identical. Cow & Gate, Kendamil, SMA, Aptamil, and supermarket brands each provide product-specific instructions.

• Check that the formula stage is suitable for your baby's age.
• Measure the water first and use only the scoop supplied with that product.
• Keep the powder-to-water ratio exactly as printed; do not dilute or concentrate formula.

A brand-neutral calculator can estimate daily intake, but the tin remains the authority for preparation. Ask a health visitor or clinician if your baby consistently takes much more or less than either guide suggests.

How Much Lactogen Should I Give My Baby Per Day?

Lactogen is a Nestlé infant formula brand sold in a number of markets, and the available products and instructions can differ by country. Use the feeding table and preparation ratio printed on the exact tin you have.

A local weight-based estimate can help you discuss total intake with a clinician, but it cannot determine Lactogen scoop counts. Never alter the concentration or use another product's scoop.

150 ml/kg Worked Example Table (3–7.5 kg)

The table below shows the arithmetic for 150 ml/kg/day. In Australia, that rate applies from 5 days to 3 months; in the UK, it is the lower end of the rough 150–200 ml/kg/day range after the first week. Do not apply this table to every age without checking the age-specific guidance above.

For a weight not shown, multiply the exact weight in kg by 150 for this worked estimate, then divide by the usual feed count. Use hunger and fullness cues rather than treating the result as a bottle quota.

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

Observable feeding and growth signs are more useful than judging intake from one 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).
• Growth over time: Weight and length trends recorded by your health visitor, child health nurse, or clinician are more useful than a single measurement.
• 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. If your baby regularly drains every bottle and still shows hunger cues, offer responsive feeds and discuss the repeated pattern with a clinician.

The Bottom Line

There is no single formula number that applies to every country and every age. NHS guidance uses a rough 150–200 ml/kg/day range after the first week, while Australian guidance reduces the rate as babies get older.

Use the calculator as a planning estimate, feed responsively, and always prepare Aptamil, Lactogen, Cow & Gate, Kendamil, SMA, or any other formula exactly as the current tin directs.

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 baby formula calculator.