What Is the Baby Weight Conversion Calculator?
Birth weight is reported in pounds and ounces in some countries (such as the US and UK) and in grams or kilograms in most of the world. This calculator converts a baby's weight between the two systems in both directions, so you can quickly understand a doctor's note, a hospital record, or a message from family abroad.
How to Use It
Pick a conversion direction. To go imperial to metric, enter the pounds and ounces and read the gram and kilogram totals. To go metric to imperial, enter the grams and the calculator splits the value into whole pounds plus the leftover ounces.
The Formula Explained
One pound equals exactly 453.592 grams and one ounce equals 28.3495 grams. To combine units: $$\text{Grams} = \text{Pounds} \times 453.592 + \text{Ounces} \times 28.3495$$ To reverse it, divide grams by 453.592 and take the whole-number part for pounds, then convert the remaining grams to ounces by dividing by 28.3495.
Worked Example
A baby weighs 7 lb 8 oz. $$\text{Grams} = 7 \times 453.592 + 8 \times 28.3495 = 3175.144 + 226.796 = 3401.94 \text{ g}$$ or about 3.402 kg. Going the other way, \(3401.94 \div 453.592 = 7\) whole pounds, leaving \(226.796 \div 28.3495 = 8\) oz.
FAQ
Is this medical advice? No. It is a unit converter only. Discuss your baby's growth with a healthcare professional.
Why are ounces sometimes shown as decimals? When converting from grams, the leftover weight rarely lands on an exact whole ounce, so a decimal gives the precise value.
What conversion factors are used? The exact international avoirdupois values: 453.592 g per pound and 28.3495 g per ounce.
