I get asked so many times, why does it not show what age a baby pattern give, instead it will be in cm or ins or both. The easy answer is because each baby is different in size at any given age. However, lets solve for the average standard size as referred to in any pattern, be it vintage or new
I know facing the dilemma of which size to knit suitable for prem babies or does it start from 3 months, dilemma is glaring you, causing unnecessary frustration on starting a lovely pattern you want to create. This is the same for children and Adults. It is expected you just measure the chest, but I hear you, you do not always have that on hand, after all we often make things for others
Standard pattern instructions normally refer to Chest measurements, but can also include:
- Sleeve length (underarm to cuff)
- Body length from underarm to hem
See the chart given below to match up to international standard sizes from 0 to 4XL
It is obviously always better to have a perfect fit, say if you making for yourself, have you noticed, some patterns, when completed you would have preferred shorter or longer sleeves or length.
This is extremely easy to adjust. Taking this example, if you fall under the M size category, it shows the sleeve will be 19ins long, but ideally, I would like one inch longer. So, what do you do now?
Extending or shortening the length
This is where Gauge verification is vitally important. The Pattern says 23 sts and 28 rows over 10 cm and/or 4 inches square swatch
As I need to lengthen by 2.5 cm (1 inch) simply divide the 28 rows by 4, even if you are working in cm, as 2.5cm x 4 gives you 10cm
This then gives you 7 rows, so all you do is continue to knit another 7 rows
Shortening the length
The same, except instead of adding you will deduct the 7 rows from the number of rows indicated in the instructions

I hope the explanation will now help you with your next project correct, just as you want it