French Drain Calculator
Plan trench material quantities for drainage runs.
Step 1: Units
Step 2
Enter project measurements
Use decimals if needed (e.g. 3.5).
Step 3
How to use this calculator
Enter trench length, width, and depth.
What the math is doing
Stone volume = length × width × depth.
Frequently asked questions
Outlet?
Daylight or dry well per code.
Socks?
Does not change gravel volume materially.
Slope?
Maintain positive flow to outlet.
Utilities?
Call 811 before digging.