French Drain Cost Calculator
French drains cost about $10–$100 per linear foot installed in 2026 — roughly $1,000–$5,000 for a typical exterior drain. Enter your drain length, type, or project below and this french drain cost calculator returns a low-to-high installed estimate with add-ons.
Interior drains cost far more than exterior ones because of concrete cutting and the sump pump. Rates shown cover trenching, perforated pipe, gravel, filter fabric, and labor.
Estimates only — not contractor quotes. Drainage cost depends on soil, depth, and local labor rates; get a licensed contractor's quote before committing to a project.
How the french drain cost calculator works
A french drain is a gravel-filled trench holding a perforated pipe wrapped in filter fabric. Water seeps through the gravel into the pipe, which carries it away from the foundation or soggy yard to a daylight outlet or sump pit. The installed price is quoted per linear foot because nearly all of the cost — trenching, pipe, stone, fabric, and labor — scales with length.
What moves the price is where the drain goes. Exterior foundation drains ($10–$35/ft) need deeper trenches and more restoration; interior basement drains ($40–$100/ft) need concrete cutting, under-slab digging, and a sump pump; simple yard drains ($10–$25/ft) are shallow and fast. Rocky soil, deep footings, permits, and putting the lawn back together all push toward the high end of each range.
base = L × r · total_lo = base_lo + sump_lo + restore_lo · total_hi = base_hi + sump_hi + restore_hi
Related tools
Keep exploring: pairing this estimate with the Foundation Repair Cost Calculator helps when water is already reaching the basement, and the Gravel Calculator sizes the drainage stone if you are pricing a DIY trench.
French drain cost calculator FAQ
How much does a french drain cost per linear foot?
Exterior french drains run $10–$35 per linear foot installed; interior basement drains cost $40–$100 per foot; simple yard or surface drains run $10–$25 per foot. A typical 100-foot exterior drain lands around $1,000–$3,500.
Why does an interior basement french drain cost more?
Interior drains cost $40–$100 per foot because the crew must cut and remove a strip of basement slab, dig below the footing, install the pipe and a sump pump, then re-pour concrete. A 100-foot basement perimeter typically totals $4,000–$10,000.
How long do french drains last?
A properly built french drain lasts 30–40 years. Silt clogging is what kills most drains early — filter fabric around the pipe and gravel, plus a cleanout for flushing, are what separate a 10-year drain from a 40-year one.
Can I install a french drain myself?
DIY materials for a 100-foot yard drain run $500–$1,000, but the trenching is heavy labor and the pipe must slope 1–2% toward the outlet — a flat or back-sloped trench just moves the puddle. Most homeowners hire out interior drains, which need concrete cutting.
How deep should a french drain be?
Yard drains are usually 18–24 inches deep; foundation drains go 24–36 inches or deeper, down to footing level. In cold climates the pipe should sit below the frost line so freeze–thaw cycles can't heave it.
Does a french drain need a sump pump?
Only if gravity can't carry water to a daylight outlet. Interior basement systems almost always need one ($800–$2,000 installed); exterior drains on a slope usually don't.
What maintenance does a french drain need?
Keep the outlet clear of leaves and sediment, flush the pipe through a cleanout once a year, and consider a camera inspection every few years. A drain that suddenly stops working is usually a clogged outlet, not a failed pipe.