The scale you order determines the amount of sequence-initiating base used to begin synthesis of your oligonucleotide. Since oligonucleotide synthesis (or any chemical reaction) is never 100% efficient, the amount of final product recovered after synthesis and purification steps (yield) will always be less than the starting amount used for synthesis. Modifications, secondary structures, and purification services further affect the final yield for a given construct. IDT offers guaranteed yields based on all of these factors that define the minimum amount of oligonucleotide you will receive for a given construct.
The minimum yield guarantee is listed in the shopping cart and in your confirmation email. To receive a higher final yield, select a larger synthesis scale. For further discussion on this topic, see the Technical Report, Oligonculdotide Yield, Resuspension, and Storage.