In order to determine how much skirting you need for a round table multiply the table size by 3.1416 to get the circumference, then divide the circumference by 12. For example: 60" round x 3.1416 = 188.50 (rounded up) / 12 = 16'
In order to determine how much skirting you will need for a long banquet table multiply the size of the table by 2 and add 5. For example: 8' table x 2 = 16 +5 = 21'
To determine how far a linen will drop on your table deduct the size of the table from the size of the table linen. Then divide that number by 2. For example: 90" round table linen - 60" table = 30/2 = 15" drop.
You can also take the size of your table and simply add 60 to determine the size of linen you will need to go to the floor. For example: 60" table + 60 = 120" table linen.