How many 50lbs bags of sand needed for 13ft diameter circle 2 inches deep?

Answer 1

30, but read below

Read the label about its coverage, but one 60 lb bag usually covers 1 cubic foot, so based on that assumption:

13ft diameter = 6.5 ft radius

2 inches deep = 1/6 ft depth

volume (cylindrical) = radius(squared)*pi(3.14)*depth

volume = (6.5^2)*(3.14)*(1/6)

volume = 22.12 cu ft

1 50lb bag covers 5/6 of a cu ft

(coverage)*(#bags)=volume

(5/6 cu ft)*(#bags)=22.12 cu ft

#bags = 26.54, rounded up = 27 bags

There will be imperfections, and tons of waste, so always get way more than you need. I'd get 30 bags and see how far that gets you, and keep in mind that a whole pallet is 42 bags, so if you wind up using much more than 30 consider just buying the pallet at a discounted wholesale price, especially if you're doing this as part of a business, because you're probably going to use the remaining bags anyways.