Each pattern will provide you with the estimated amount of yarn needed for each size. This will almost always be in both grams and meters. If you are knitting with a yarn with the same meters/100g as the suggested yarn you can make your yarn purchase based upon the number of grams needed. However if you are using a yarn with a different meters/100g you should purchased your yarns based upon the total meters required for your size. When buying yarn take into consideration that if you plan to lengthen the body or sleeves you will need more yarn.

 

It is also worth pointing out that I DO NOT overestimate the amount of yarn you will need, as such the amount stated is more or less exactly what you will need, this is to prevent you from having loads of yarn left over, but it does mean that if you plan to make any modifications you should buy more yarn than stated. Each of my patterns also has a section at the end of the pattern that gives you information on the yardage and yarn used by test knitters along with any modifications they made. This is really handy if you plan to use a different yarn to the suggested yarn.