See pic of a corner post See Fencing Diagram 5. Count the number of blank posts you will need. Blank posts have no holes at all. They would be used on the side of a gate. To insure you are not shorted on the number of posts needed, go through the following two steps.
More material is better than being shorted and paying shipping costs on additional material.
Our gates, are a gate kit. This means you will use the rails from the fence to complete the gate. This is so you can cut the rails to fit your gate opening. Now, count the number of times your fence lines do not touch another fence. This will give you the number of additional posts needed to complete your fence.