Calculate How Much Driveway Gravel You Need | DoItYourself.com
Step 2 – Calculate the Volume. To calculate the volume, multiply the three measurements, length by width by depth. For instance, if you have a gravel driveway that is 36 feet long, 9 feet wide, and 3 inches deep, multiply: 36 x 9 x .25 = 81 cubic feet of gravel. You now know that 81 feet cubed is the amount of gravel you need.