How this calculator works
Soggy yards and wet foundations have the same cheap, ancient cure — a ditch that water prefers. The price depends almost entirely on how deep that ditch has to be.
Depth is the price lever
All three options in this tool are the same sandwich — trench, filter fabric, perforated pipe, washed gravel — at different depths. A shallow yard drain fixes puddling grass. A standard drain at 18–24 inches intercepts water heading for a foundation or patio. A deep curtain drain cuts off hillside groundwater before it reaches the house. Double the depth means far more than double the digging, hauling, and gravel, which is why the per-foot ranges spread so widely.
The two details that decide success
First, slope — the pipe needs a steady fall (about 1 inch per 8–10 feet) toward somewhere water can legally and usefully go: daylight, a dry well, a storm connection. No discharge point, no drain. Second, filtration — fabric and washed gravel keep soil out of the pipe. Most “my French drain stopped working” stories are a clogged, fabric-less trench.
DIY or dig out the checkbook
A shallow run in soft soil is one of the best money-saving DIYs in the yard: materials are cheap and the toggle shows what the trench labor is worth. Call 811 before any digging. For deep drains, foundation work, or rocky ground, the pro’s trencher earns its fee fast. If the water problem starts at a retaining wall, see the retaining wall calculator — drainage is half of that job too.
2026 installed French drain cost per linear foot
Exterior drains, installed — trenching, filter fabric, perforated pipe, drainage gravel, and backfill. Interior basement perimeter systems are a different, pricier animal.
| Option | Low (per linear ft) | High (per linear ft) | Typical (per linear ft) |
|---|---|---|---|
| Shallow yard drain (10–12 in) | $10 | $30 | $20 |
| Standard French drain (18–24 in) | $25 | $60 | $40 |
| Deep / curtain drain (3 ft+) | $40 | $90 | $65 |
Estimated cost by state
Typical installed range for a 50 ft standard exterior French drain, installed, adjusted by each state's construction cost index. Your actual project scales with the size and options you enter above.
| State | Estimated low | Estimated high |
|---|---|---|
| Alabama | $1,075 | $2,580 |
| Alaska | $1,438 | $3,450 |
| Arizona | $1,200 | $2,880 |
| Arkansas | $1,100 | $2,640 |
| California | $1,400 | $3,360 |
| Colorado | $1,225 | $2,940 |
| Connecticut | $1,338 | $3,210 |
| Delaware | $1,200 | $2,880 |
| District of Columbia | $1,250 | $3,000 |
| Florida | $1,163 | $2,790 |
| Georgia | $1,125 | $2,700 |
| Hawaii | $1,600 | $3,840 |
| Idaho | $1,213 | $2,910 |
| Illinois | $1,438 | $3,450 |
| Indiana | $1,275 | $3,060 |
| Iowa | $1,250 | $3,000 |
| Kansas | $1,175 | $2,820 |
| Kentucky | $1,175 | $2,820 |
| Louisiana | $1,138 | $2,730 |
| Maine | $1,200 | $2,880 |
| Maryland | $1,200 | $2,880 |
| Massachusetts | $1,475 | $3,540 |
| Michigan | $1,263 | $3,030 |
| Minnesota | $1,400 | $3,360 |
| Mississippi | $1,113 | $2,670 |
| Missouri | $1,350 | $3,240 |
| Montana | $1,250 | $3,000 |
| Nebraska | $1,200 | $2,880 |
| Nevada | $1,275 | $3,060 |
| New Hampshire | $1,250 | $3,000 |
| New Jersey | $1,475 | $3,540 |
| New Mexico | $1,125 | $2,700 |
| New York | $1,375 | $3,300 |
| North Carolina | $1,163 | $2,790 |
| North Dakota | $1,263 | $3,030 |
| Ohio | $1,325 | $3,180 |
| Oklahoma | $1,150 | $2,760 |
| Oregon | $1,300 | $3,120 |
| Pennsylvania | $1,275 | $3,060 |
| Rhode Island | $1,363 | $3,270 |
| South Carolina | $1,175 | $2,820 |
| South Dakota | $1,163 | $2,790 |
| Tennessee | $1,175 | $2,820 |
| Texas | $1,138 | $2,730 |
| Utah | $1,213 | $2,910 |
| Vermont | $1,238 | $2,970 |
| Virginia | $1,150 | $2,760 |
| Washington | $1,363 | $3,270 |
| West Virginia | $1,175 | $2,820 |
| Wisconsin | $1,325 | $3,180 |
| Wyoming | $1,175 | $2,820 |
Frequently asked questions
How much does a French drain cost in 2026?
Exterior drains run about $10–$30 per linear foot for a shallow yard drain, $25–$60 for a standard 18–24 inch drain, and $40–$90 for deep curtain drains. A typical 50-foot standard run lands around $1,250–$3,000 before state adjustments.
What exactly is a French drain?
A gravel-filled trench with a perforated pipe at the bottom, wrapped in filter fabric. Water seeps into the gravel, enters the pipe, and flows by gravity to a discharge point — a curb, dry well, or daylight on a slope. No pump, no moving parts, which is why they last decades when built right.
How deep does the drain need to be?
It depends what you're protecting. Soggy-lawn surface water needs only 10–12 inches. Redirecting groundwater away from a foundation wants 18–24 inches or more, and true curtain drains intercepting a hillside run 3 feet plus. Deeper digging is most of the price difference.
Can I dig a French drain myself?
A shallow yard drain is honest DIY — the materials are cheap and the toggle shows the savings. Know that trenching is brutal hand labor (or a trencher rental), the pipe needs a consistent 1% slope, and you must call 811 for utility locates before digging. Deep drains near foundations are pro work.
Why do French drains fail?
Almost always clogging — soil fines get in because the fabric was skipped or the gravel was wrong, or the outlet gets buried or blocked. Built with proper fabric, washed gravel, and a protected discharge point, a drain should work for 20–30 years.
Disclaimer: Estimates are for planning only and reflect typical ranges, not quotes. Actual costs vary with site conditions, design complexity, local permits, and contractor availability. Pricing approach: national averages cross-referenced from public cost guides, adjusted by a state construction cost index — see our methodology.
Price data sources: LawnStarter, French drain cost 2026 — exterior $10–$65 per linear foot (interior $40–$100); 50 lf exterior $500–$3,250; DIY materials (pipe, gravel, fabric, trencher rental) versus ~$3,000 professional: https://www.lawnstarter.com/blog/cost/french-drain-price/; Lawn Love, French drain cost 2026 — exterior $10–$75 per linear foot; national average $5,000, typical $2,800–$6,500; sump pump add-on $625–$2,625; DIY materials ~$21 per linear foot: https://lawnlove.com/blog/french-drain-cost/; HomeGuide, French drain cost 2026 — yard/curtain drains $10–$35 per linear foot; deeper foundation-side drains $30–$90 per foot: https://homeguide.com/costs/french-drain-cost; HomeGuide, drainage system installation cost 2026 — exterior yard drainage per-foot ranges by depth: https://homeguide.com/costs/drainage-system-installation-cost. Last updated: September 2026.