French Drain Calculator
Construction & Home ImprovementCalculate the gravel volume and weight needed for a French drain trench, after accounting for the drain pipe.
Gravel Volume Needed
Volume of gravel needed to fill the trench around the drain pipe.
Gravel Weight
3.532
Estimated gravel weight, in US tons.
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Creators
Odeh Ahwal0people find this calculator helpful
Views
Helpful
Saved
Embeds
Construction & Home Improvement calculators
Frequently Asked Questions
Why subtract the pipe volume from the trench volume?
The perforated drain pipe itself takes up space inside the trench, so the gravel only needs to fill the remaining space around and above it, not the full trench volume.
What trench dimensions are typical for a French drain?
A common residential French drain trench is about 12 to 18 inches wide and 18 to 24 inches deep, though this varies with the amount of water the drain needs to handle and local soil conditions.
Should I use round gravel or crushed stone?
Crushed, angular stone is generally preferred over smooth round gravel for French drains, since angular pieces interlock and leave more open void space for water to flow through, and resist settling and shifting better over time.
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