My rule of thumb is that pulls look best when they are about 1 3 the width of the drawer.
Standard drawer pull sizes.
3 one or two 4 one or two 96mm and 128mm.
If a group of cabinet drawers are stacked on top of one another and they all have the same width but different heights use the same length cabinet pull for all drawers.
For standard size cabinetry dimensions of 12 36 the most common pull sizes are 3 4 96mm and 128mm center to center from one screw hole to another.
Standard knob sizes are 1 1 4 or 1 3 8.
Knobs on the doors is a good choice for a traditional or transitional kitchen.
On your island use either 7 or 8 pulls on the 21 24 drawers and use 10 on the pot drawers and the pull down drawer under the sink.
Oversize drawers 36 or larger for larger drawers consider investing in longer length stainless steel pulls such as 6 8 10 or even 12.
Standard size pull handles normally have center to center fastener hole measurements of 3 4 96mm or sometimes smaller.
Most people will choose two or three different sizes to fulfill all their kitchen cabinet hardware needs.
All of the sizes i mentioned above so if you need to review that again.
Decorative standard sized cabinet pulls drawer handles with decor appeal functional style.
Common cabinet hardware pull installation by size.
The graphic below shows is a nice visual of approximately how each common size of pull will look on a cabinet drawer or door.