Baby Weight Converter
Convert birth weight between grams, kilograms, and pounds and ounces — correctly. Enter any value and all three update instantly.
Why this calculator shows ounces correctly
Most online converters display baby weight as decimal pounds — for example, 3.4 kg becomes 7.5 lbs or 7.49 lbs. That is not a weight anyone recognises or can use. It is a fraction, not a measurement.
This calculator always converts to whole pounds and whole ounces — because that is how families ask, remember, and share a baby's birth weight. Clinical records use grams or kilograms; this converter is for the moment a grandparent asks "but how much is that in pounds?"
Common birth weight reference
| Grams | Kilograms | Pounds & Ounces | Note |
|---|---|---|---|
| 1000 g | 1.000 kg | 2 lbs 3 oz | Very preterm threshold |
| 1500 g | 1.500 kg | 3 lbs 5 oz | Preterm — intensive care |
| 2000 g | 2.000 kg | 4 lbs 7 oz | Preterm — special care |
| 2500 g | 2.500 kg | 5 lbs 8 oz | Low birthweight threshold |
| 3000 g | 3.000 kg | 6 lbs 10 oz | Normal range |
| 3175 g | 3.175 kg | 7 lbs 0 oz | 7 pounds exactly |
| 3400 g | 3.400 kg | 7 lbs 8 oz | Average NZ birth weight |
| 3500 g | 3.500 kg | 7 lbs 11 oz | Normal range |
| 4000 g | 4.000 kg | 8 lbs 13 oz | Large for gestational age threshold |
| 4500 g | 4.500 kg | 9 lbs 15 oz | Macrosomia threshold |
About this tool
This calculator was built by a New Zealand midwife to solve a daily frustration: no freely available converter displayed birth weight in whole pounds and ounces — the way families actually ask for it.
New Zealand uses metric weights in clinical documentation. Pounds and ounces remain the way many families — particularly those from the United Kingdom, United States, Pacific Island communities, and older generations — understand and remember birth weight. Being able to give a clear conversion is part of good communicative care.
More midwifery calculators are in development. If you have a conversion or tool you find yourself calculating repeatedly, let us know.