One cubic yard of product will cover an area approximately 10 feet by 10 feet and to a depth of 3 inches.
Three inches is generally regarded as the standard for ground covers, as there will be enough product to cover the ground sufficiently without seeing exposed ground. Obviously this is just a suggestion, and the amount you lay down should be considered based on the purpose of the ground cover and the amount of traffic that the area will see.
If you are unsure about how much material you need, we have a calculator on the front page of our website that you can use, or you can give us a call and we will help you with your measurements.