According to eHow, your base area must support at least 1/3 of the table top area.
Circumference of a circle is 2*pi*radius or pi*diameter. Therefor, if the circumference of the table is 15.7 cm then its diameter is 15.7/pi = 4.9975 cm or roughly 5 cm. So the circumferences and diameters of the table and its leg are equal.
About 7/8 foot
113.04m2 (120/2x120/2x3.14)
c = 3.14 x the diameter
Each person requires at least a 24 inches for eating space. This means a 4 ft diameter table will fit 6 people. That is a bit crowded though, so I would shoot for 30 inches instead. That would mean you should have 5 foot diameter table for 6 people.
If the table is 60 inches across, the diameter is 60 inches.
Depending on the people, you need to figure about 36 inches of space per person. So a table for 24 would need to have a perimeter of 72 feet! If the table is required to be round, then a diameter of 72/pi or 23 FEET is required. Nobody has a table that's 23 feet in diameter. King Arthur's mythical Round Table may have been that size, perhaps. If it existed, it was probably toroidal (doughnut-shaped, with a hole in the center) to allow servants to put food on the table.
According to eHow, your base area must support at least 1/3 of the table top area.
Check the link below for the table and seating capacities http://www.weparty.com/guides/planningguide_tableseating.pdf http://www.stuartrental.com/party-rentals/7/table-rentals FROM BUYAGAN, LA TRINIDAD ARCHITECT
If the table is a circle and the perimeter is 40 feet, then the diameter (rounded to 2 decimal places) would be 12.74 circumference = diameter x pi so, diameter = circumference / pi
At least: pi*0.75*0.75 = 1.767 square meters rounded to 3 decimal places The circumference of the table is: 1.5*pi
900
123.14"
234
Its 26 cause radius is half of a diameter so u multiply 13 by 2
If the dining table diameter is 36" (900mm), a rug underneath this table should be sized so that it is large enough to be beyond the chair legs when a chair is in the pulled out position. This means it will not catch on the chair as the person seats themselves and pulls the chair in. A rug that extends at least 48" (1200mm) beyond each side of the table would be required. This gives a total diameter for the rug of at least 130" (3300mm).