Pick the kind of drain, type its length and the trench, and say where the water goes. You get what a pro charges at HomeGuide's price a foot, two other guides' prices beside it, and for a drain outside, every material to do it yourself: the drainage rock by the ton, the pipe, the filter fabric, the fittings and the trencher.
Your french drain
$500–$1,500 by a pro · $330–$680 yourself50 ft surface drain, 12″ wide, 12–18″ deep, to daylight · HomeGuide, 2025 prices
Quick answer: a 50 ft french drain in the yard, 12″ wide and 12″ deep, costs $500–$1,500 by a pro at HomeGuide’s $10–$30 a foot. Put in yourself it costs $330–$680: 2.8 tons of drainage rock, 50 ft of 4″ perforated pipe, 225 sq ft of filter fabric, two fittings and a trencher for a day. Change the kind of drain, its length or the trench above and the prices follow.
How to use the french drain cost calculator
- Pick the kind of drain. A surface drain is a shallow gravel trench that shows. A curtain drain is deeper and hides under soil and sod. A footing drain runs beside the house’s footings. Crawl space and basement drains go inside the house.
- Type the drain’s length, from the wet spot to where the water leaves.
- For a drain outside, type the trench: its depth at the high end and its width. Say whether the ground is flat (the trench gets deeper toward the outlet) or already falls that way. Then pick gravel to the top or soil over it, the pipe, where the water goes, and how you dig.
- You get a pro’s price for those feet, LawnStarter’s and Lawn Love’s prices beside it, and for a drain outside every material to do it yourself, each with its price. Copy link keeps your drain. The green button opens the gutter size calculator, to size the downspouts that feed the drain.
What a french drain costs by a pro
HomeGuide prices a french drain by the foot, and the kind of drain sets the price. A surface drain in the yard is $10–$30 a foot. A curtain drain is $10–$35, because it goes deeper. A footing drain at the foundation is $30–$90, because the digging goes down to the footings. Inside, a crawl space drain is $20–$40 a foot and a basement drain $40–$85, because the floor along the walls is broken out and the drain runs to a sump pump. HomeGuide: “Interior drainage systems typically include a sump pump.”
| Kind of drain | A foot | 50 ft | 100 ft | 200 ft |
|---|---|---|---|---|
| Surface drain in the yard | $10–$30 | $500–$1,500 | $1,000–$3,000 | $2,000–$6,000 |
| Curtain drain | $10–$35 | $500–$1,750 | $1,000–$3,500 | $2,000–$7,000 |
| Footing drain around the house | $30–$90 | $1,500–$4,500 | $3,000–$9,000 | $6,000–$18,000 |
| Crawl space drain | $20–$40 | $1,000–$2,000 | $2,000–$4,000 | $4,000–$8,000 |
| Basement drain, inside | $40–$85 | $2,000–$4,250 | $4,000–$8,500 | $8,000–$17,000 |
Two other guides price it more widely. LawnStarter (October 2026) gives $10–$65 a foot outside and $40–$100 inside; Lawn Love (December 2025) gives $10–$75 outside and $40–$100 inside. Both put the average job at $5,000. A dry well where there is nowhere for the water to go adds $200–$700 for a plastic tank, and a sump pump adds $600–$2,500. A permit, where your town asks for one, is $100–$375 more.
What it costs to put in a french drain yourself
For a drain outside, the calculator lists the materials and prices each one. LawnStarter’s own estimate: “The total cost to do this project on your own is about $700 vs. $3,000 to have a professionally installed French drain.”
- Drainage rock: ¾″ washed gravel by the ton, delivered, at $25–$50 a ton (HomeGuide’s gravel price table). The calculator fills the trench, takes out the pipe’s room, and weighs it at 2,565 lb a cubic yard. Skip pea gravel. The drain maker Amerimax: “Be sure to avoid small pea gravel or crushed rock.”
- The pipe: 4″ perforated pipe, $1–$3 a foot for corrugated or $1.20–$5 for PVC in 10 ft lengths. A filter sock adds $0.25–$0.70 a foot.
- Filter fabric: $0.45–$0.80 a square foot (LawnStarter). The strip lines the floor and both sides of the gravel and folds over the top, so it is twice the trench’s width plus twice the gravel’s depth.
- Fittings: $7 each, for an end cap, the outlet, and a coupler between pipe lengths.
- Digging: a trencher for a day, $100–$200, or a $20 shovel. HomeGuide: “Installing a shallow French drain takes up to a day in an easily accessible yard that does not require resloping.”
How deep and how wide the trench is
HomeGuide: “A French drain should be 12″ to 24″ inches deep, at least 12″ wide, and 2 to 5 feet away from the home’s foundation in most cases.” The trench has to fall toward the outlet: “The drain must run away from the property on a slope of at least 1%, or 1′ lower for every 100′ of drain.” On flat ground that fall comes from digging deeper as you go, so the calculator adds 1.2″ for every 10 ft. A 50 ft trench that starts 12″ deep ends 18″ deep at the outlet.
The pipe sits on gravel and is covered by it: “An ideal French drain has 2 to 3 inches of gravel under the pipe and about 3 to 4 inches covering the pipe.” The calculator lays a 4″ pipe on 3″ of gravel and covers it with 4″, an 11″ bed. A surface drain is gravel to the top. A curtain or footing drain has soil and sod over the bed. HomeGuide warns: “Covering a French drain with dirt slows and may stop the drainage process, depending on the soil type.” The fabric is what keeps that soil out of the gravel: “Wrapping the gravel and pipe with non-woven geotextile fabric and covering with more gravel or turf grass with 1 to 2 inches of attached roots works best in most regions.”
| Trench width | 12″ deep | 18″ deep | 24″ deep |
|---|---|---|---|
| 9″ | 0.31 tons (0.25 cu yd) | 0.49 tons (0.38 cu yd) | 0.67 tons (0.52 cu yd) |
| 12″ | 0.43 tons (0.34 cu yd) | 0.67 tons (0.52 cu yd) | 0.91 tons (0.71 cu yd) |
| 18″ | 0.67 tons (0.52 cu yd) | 1.03 tons (0.80 cu yd) | 1.38 tons (1.08 cu yd) |
Worked examples
- A 100 ft curtain drain, 24″ deep, soil on top, on flat ground: it ends 36″ deep at the outlet. A pro charges $1,000–$3,500. Yourself it is $480–$1,020: 3.9 tons of drainage rock ($98–$200), 100 ft of corrugated pipe ($100–$300), 383 sq ft of fabric ($170–$310), two fittings and a trencher.
- The default yard drain, emptying into a dry well: $700–$2,200 by a pro and $530–$1,380 yourself. The plastic dry well tank adds $200–$700 to both.
- A 150 ft footing drain, 48″ deep and 18″ wide, in PVC: $4,500–$13,500 by a pro. On flat ground it ends 66″ deep, past OSHA’s limit: “Trenches 5 feet (1.5 meters) deep or greater require a protective system unless the excavation is made entirely in stable rock.” Hire this one out.
- A 120 ft basement drain: $4,800–$10,200 by a pro on HomeGuide’s figures, and $4,800–$12,000 on LawnStarter’s and Lawn Love’s. The sump pump is part of the job.
Common mistakes
- No fall. A level trench holds water. On flat ground, dig 1″ deeper for every 8 ft or so, toward the outlet.
- The wrong gravel. Pea gravel and crushed rock clog the pipe’s holes. Buy washed ¾″ drainage rock.
- A sock instead of fabric. HomeGuide: “Lining the trench with geotextile fabric instead is a better choice to prevent clogging.”
- Nowhere for the water to go. The outlet has to be lower than the trench’s bottom, and never your neighbor’s yard. With no low ground, budget for a dry well or a sump pump.
- Digging before calling 811. “Call 8-1-1 to have utility lines marked before the work begins to prevent issues.”
Questions
How much does french drain installation cost?
By a pro, $10–$30 a foot for a surface drain in the yard and $10–$35 for a curtain drain (HomeGuide, 2025), so $500–$1,500 for 50 ft and $1,000–$3,000 for 100 ft of surface drain. A footing drain is $30–$90 a foot, a basement drain $40–$85.
What is the french drain cost per foot?
HomeGuide: $10–$30 for a surface drain, $10–$35 for a curtain drain, $30–$90 for a footing drain, $20–$40 in a crawl space and $40–$85 in a basement. LawnStarter’s range is $10–$65 outside and $40–$100 inside.
How much does it cost to put in a french drain yourself?
For 50 ft of 12″ × 12″ trench, about $330–$680: drainage rock, pipe, filter fabric, two fittings and a trencher for a day. By hand with a shovel, about $250–$500. LawnStarter puts a typical DIY job at about $700.
How much gravel do I need for a french drain?
About 0.43 tons for every 10 ft of a 12″ × 12″ trench filled to the top, with a 4″ pipe inside. With soil on top, only the 11″ gravel bed around the pipe. The calculator works it out for your trench in tons and cubic yards.
How much does a french drain system cost with a sump pump?
Outside, a sump pump adds $600–$2,500 to the drain (HomeGuide). Inside the house, a crawl space or basement drain’s price already includes the sump pump.
How long does a french drain last?
“Most French drains last 30 to 40+ years when installed correctly.” Fabric around the gravel and the right drainage rock are what keep it from clogging.
Read next
- Fire pit on a sloped yard
- Rock landscaping ideas
- Rainwater collection system ideas
- Hot tub pad ideas
- Paver patio ideas
- Backyard landscaping designs
Water pouring off the roof onto one spot? The free gutter size calculator sizes the gutters and downspouts that feed the drain. The 2D planner draws the yard and the house to scale, so you can plan where the drain runs.
Sources, read October 19, 2026: HomeGuide, How Much Does a French Drain Cost? (2025 prices) and its gravel prices (December 19, 2025), both through the Internet Archive; LawnStarter, French drain cost (updated October 5, 2026); Lawn Love, French drain cost (updated December 27, 2025); the Amerimax Flex Drain installation guide; OSHA’s trenching fact sheet; the Cubic Yardage Chart’s gravel weight. Prices change: the calculator’s are re-read every six months.