The amount of fake snow in each package is measured by the gallons it will produce.
To better help you decide how many gallons of Snow in Seconds^TM you need, use the equation;
Width x Length x Desired Depth= Volume/.134 (Cubic Feet in a Gallon).
This equals the amount of gallons you will need to cover your intended area.

VIDEO

http://www.effectspecialist.com/Snowoptions.htm#proseries

http://www.sno-wonder.com/order.asp