French Drain Gravel Calculator
Trench prism minus conservative pipe displacement (ignored for small pipes).
Step 1: Units
Step 2
Enter project measurements
Use decimals if needed (e.g. 3.5).
Step 3
How to use this calculator
Trench width, depth, and run length.
What the math is doing
Volume = length × width × depth.
Frequently asked questions
Sock pipe?
Does not change order quantity materially.
Outlet daylighting?
Slope trench toward discharge.
Fabric?
Add roll length × width.
Inspection ports?
Accessory count.