Is 0-3 Months The Same As 3 Months? (Explained!)

Yes. When we say 0-3 Months old baby size, it is synonymous with 3-months old baby size.

However, 0-3 months old are babies aged between 1 to 14 weeks old, thereabouts, while three-month-Old babies have clocked 15 weeks old and slightly above.

Meanwhile, when your baby clocks three months, it is a growth stage when they begin to develop stronger attachment with their parent or whosoever takes care of them.

To effectively calculate the month old of your baby, that is, converting the baby’s age from weeks to a month to know whether it is 3 months, all you should do is divide the number of weeks by 4.345.

For example, suppose the baby is 15 weeks old. In that case, you will divide 15 by 4.345, which is approximately 3 months.

This way, we can clarify the actual ages for newborns in terms of months.

What size baby is 0 to 3 months?

For infants clothes that has the label of ‘size 0-3 month’, only newborns who weigh about 7 pounds and perhaps 12.5 pounds maximum can achieve snug fit in them.

Babies clothes size in this category are usually measured 21 inches long. But some can be as long as 24 inches depending on the cloth and size type.

Meanwhile, even 2 weeks old babies can wear cloth sizes meant for 0-3 months as they come in different sizes and body shapes.

Many parents find it difficult to understand which clothing size will fit their baby, especially beginning from 0-3 months cloth size.

This is because sizes marked on the cloth label make it appear to be based on the baby’s age. In contrast, it is based on size.


What size are up to 3 months?

In the basic sense, baby clothes are sized by age. In other words, buying pieces that tally to your baby’s age should be the ideal thing.

However, babies come in different shapes and sizes, so there is no straight rule guiding the sizing of babies when shopping for their clothes.

Cloth size that will fit 3-month-old baby size can also be used for babies that are not yet up to 3 months old.

So if a baby cloth label reads ‘3 months,’ it can be assumed that the cloth will fit babies that are between 0-3 months old, just as the way cloth label that reads ‘6 months’ can fit babies who are somewhere between 3-6 months old.

What’s the difference between the newborn size and 0-3 months?

There isn’t a difference between the sizes of newborns and those within 0-3 months because the latter covers size of newborns.

However, sizes 0-3 months should fit your baby if he weighs 12 pounds. But newborns who get cloth sizes of 0-3 months will not look snug fit, but you can always fold the sleeves and pant legs for a few weeks while the baby grows bigger over time.

What size does newborn wear?

Newborns wear a cloth size of Size 000. This size will fit snugly for babies between 0 to 3 months.

However, infants older than 3 months but not over 6 months can wear cloth size 00.

Meanwhile, some newborns are bigger and can wear up to size 00. You’d have to buy the size label for 3-6 months and then fold up the sleeves up. This won’t be for long.

Nevertheless, the size of clothes for babies varies as per the manufacturer and type of cloth in question.

How long are babies considered newborns?

Babies from birth up to 2 months old are considered newborns, while babies between the day of delivery and one year old can be called an infant.

The term child refers to babies between the day of birth to 4 years old. In other words, the latter can be referred to as infant, or even toddler.

When to move up a size in baby clothes?

It is a general rule to move up a size when shopping for baby clothes. This is also ideal when you can’t tell the exact size of the baby.

People consider it a wise choice to go for the 3-6 month (or larger) size range when shopping for the 0-3 month range.

This is because babies really do grow very fast. So, moving up a size or not, it would be best to moderate the number of clothes you buy in each size.


Most parents will agree that baby clothes sizes are more confusing than complicated. It is expected because determining the size of newborns comes with no frame of reference.

In the above article, we’ve been able to identify whether or not there is a difference between 0-3 months and 3 months baby sizes.

We have also touched on the various factors usually considered when baby cloth sizes come into question.