The typical koi pond cost ranges between $5,100 to $15,875, but the price changes with size and add-ons. You can buy a small prefab koi pond with a basic filtration system for as low as $500. For large custom-made koi ponds with extensive landscaping, waterfalls, jets, and aquatic plants, costs can reach $80,000.
Growing koi is a long-term investment and also includes pond maintenance costs. Expect to pay $1,000 to $2,000 yearly as the average cost to maintain a koi pond. This includes pond and filter cleaning and repairs.
Read more in this cost guide about:
- Average costs
- Cost estimator by size
- Other factors that affect cost
- Related services
- Cost by location
- FAQ
Average koi pond costs in 2024
Most homeowners pay $5,100 to $15,875 to install a good quality koi pond in their backyard, with an average cost of $10,500.
| National average cost | $10,500 |
| Typical price range | $5,100 – $15,875 |
| Extreme low-end cost | $500 |
| Extreme high-end cost | $80,000 |
The typical price range given above is for mid-sized koi ponds of 6×8 feet to 11×16 feet, costing $50 to $130 per square foot. Keep in mind these are only estimates, and costs vary widely with size, equipment, decorative features, and fish.
Expect to pay more towards the high end of the price range if:
- The pond is larger than average
- You decide on a concrete koi pond
- The landscape design is more complex, and the pond has an irregular shape
The way to save money when building a koi pond is to keep it simple:
- Go for a prefabricated koi pond liner.
- Create a minimalist design.
- Choose small, domestic koi. They are lovely and playful and will grow in time.
Koi pond cost estimator by size
The size of your backyard pond determines the cost of the liner, pump, filter, skimmer, and UV light. A large koi pond will also need more landscaping. You can install a small pond for $2,800 to $7,280, while projects of 21 x 26 feet go up to $80,000.
| Project size | Average overall cost |
| 7×8 feet | $2,800 to $7,280 |
| 8x11feet | $4,400 to $11,440 |
| 10×14 feet | $7,000 to $18,220 |
| 11×16 feet | $8,800 to $22,880 |
| 16×21 feet | $16,800 to $43,680 |
| 21×26 feet | $27,300 to $70,980 |
For growing happy and healthy koi fish, experts recommend at least a 7 x 8-foot surface, with a depth of 3 – 4 feet.
Other factors that affect cost
The size of the pond is the primary cost factor, but other elements can significantly affect your budget.
Koi pond construction costs
A new pond requires excavation, edging, and landscaping. Some pond contractors include grading and leveling in excavation costs, and some don’t. Here are the costs you should consider for these services.
| Koi pond construction services | Average cost |
| Permit for digging and grading | $150 to $485 per project |
| Excavation | $60 to $200 per cubic yard |
| Grading and leveling | $40 to $180 per hour |
| Pond liner | $0.30 to $113.50 per square foot |
| Edging | $700 to $1,750 per project |
Permit
Permits for digging and grading typically cost $150 to $485. The size of the pond, location, and county laws can impose additional permits and fees, so make sure you check before digging.
Excavation
Excavation cost ranges from $60 to $200 per cubic yard. This takes the price of digging a small koi pond of 7×8 feet, 4 feet deep, to about $500 to $1,660. Pond builders recommend a minimum depth of 3 feet, without shallow shelves for aquatic plants, to protect fish from raccoons and herons.
Koi pond liner
Koi pond liners cost from $0.30 to $113.50 per square foot, depending on the material. You can calculate pond liner size using this formula:
- Liner size = (Pond Length + (2 x Pond Depth + 1)) x (Pond Width + (2 x Pond Depth + 1))
Don’t be intimidated by the formula! It’s really not as complicated as it looks. Here’s an example for a 7×8-foot pond at 4 feet deep:
Step 1: Plug in your numbers.
(7 feet + (2 x 4 feet + 1)) x (8 feet + (2 x 4 feet + 1))
Step 2: Start with the numbers in double parentheses.
(7 feet + 9 feet) x (8 feet + 9 feet)
Step 3: Now, find the sums of the numbers in parentheses.
16 feet x 17 feet
Step 4: Multiply the numbers you have left.
16 feet x 17 feet = 272 square feet
So, this example pond needs a 272-square-foot liner, which could cost anywhere from $82 – $40,000 depending on the material.
Here are the average prices for the most popular koi pond liners.
| Koi pond liner | Average cost per square foot |
| HDPE | $0.30 to $0.70 |
| HDPE pre-formed tank | $3.40 to $7.40 |
| RPE | $0.45 to $1.65 |
| Non-toxic EPDM | $0.65 to $2.30 |
| Fiberglass pre-formed tank | $10 to $80 |
| Concrete | $63.50 to $113.50 |
PVC liners are unsafe for fish, so you should avoid them for koi ponds.
Edging and curbing
Use gravel, river rock, or boulder edging and curbing to conceal the liner and integrate the water feature into your garden design. Landscape curbing cost ranges from $700 – $1,750 and varies with pond size and material.
Koi pond add-ons
Homeowners pay $7,000 to $18,200 for a mid-sized 10×14 koi pond. Prices can change depending on what add-ons you choose. See below what add-ons you should consider and their associated costs.
| Koi pond add-ons | Average cost |
| Landscaping | $4.50 to $17 per square foot |
| Pond filter | $150 to $1,300 per filter |
| Circulation pump | $50 to $2,000 per pump |
| Pond skimmer | $100 to $700 per skimmer |
| Return jets | $10 to $50 per jet |
| Auto-fill valve | $30 to $100 per valve |
| UV light | $55 to $600 per light |
| Koi fish | $15 to $55 per fish |
Koi pond filter
Pond filters cost $150 to $1,300 and keep the water clean and clear by capturing leaves and other debris. They also convert harmful nitrites, from degraded fish food and waste, into harmless nitrates.
To choose the best filtration system, multiply your backyard pond’s volume by 1.5 and look for a filter with this capacity or higher. Here are the average filter costs for the most popular koi pond sizes.
| Size | Filter capacity required | Average cost |
| 7×8 | 2,520 | $150 – $400 |
| 8×11 | 3,960 | $200 – $500 |
| 11×16 | 7,920 | $700 – $900 |
| 16×21 | 15,120 | $1,000 – $1,300 |
| 26×26 | 30,420 | $2,000 – $5,000 |
Circulation pump
The average pond pump cost ranges from $50 to $500 for small and medium koi ponds. For larger projects, consider investing up to $1,000 or $2,000. A good koi pond pump must circulate the entire water volume at least once every three hours.
Pond skimmer
Depending on the pond size, a pond skimmer costs $100 to $700. It collects leaves, algae strings, and other large debris from the top layer of the water.
Return jets
Jets cost $10 to $50 apiece and work with the waterfall to circulate water efficiently. They send debris from every pond corner to the skimmer and bottom drain. Jets also create current areas for the koi fish to play in.
Auto-fill valves
A pond auto-fill valve costs $30 to $100 and adds water to the pond when the volume lowers due to evaporation, cleaning filters, or changing water.
UV light sterilizer
To prevent algae blooming, use UV light sterilizers. You can buy one for $55 to $600. Single lamp units are more cost-effective and easier to replace.
Koi fish
What’s a koi pond without koi fish? Koi are more expensive than your average goldfish, costing $15 to $55 per fish, and their prices vary widely. You can buy small, affordable, domestic koi at $2.55 per fish or invest over $8,000 in a huge, 29.5-inch Showa Isa imported from Japan.
The cost of a koi pond increases when you have to add related services such as land clearing or installing retaining walls. Functional and decorative add-ons like pond heaters, auto feeders, and underground lights can also raise your budget.
Koi pond maintenance cost
Koi pond owners pay $1,000 to $2,000 per year for maintenance. The service includes spring, summer, and fall cleaning, repairs, and preparing the pond for winter.
Land clearing
Before digging the koi pond, you need to clear the yard of all obstacles (trees, stumps, boulders, bushes, etc). The cost to clear land is $120 to $265 per hour.
Retaining walls
Build beautiful retaining walls around your koi pond to make it more attractive or raise the water level. The average retaining wall cost is $40 to $345 per linear foot.
Auto feeder
For $100 to $125, you can buy an automatic pond fish feeder to feed the koi. Still, professional koi breeders recommend feeding the fish by hand at least once a day to check their health.
Landscape lighting
Landscape lighting cost is $2,100 – $4,900 per project. You can expect to pay $100 to $400 per fixture for underwater LEDs. Installing them doubles the time you can enjoy your koi pond and creates the unique experience of watching koi fish swimming at night.
Pond heater
Pond heaters keep a section of the pond’s surface from freezing, letting oxygen in and toxic gasses out. You can buy a pond heater for $38 to $135 per unit.
Waterfall
A waterfall is a lovely addition to your koi pond and typically costs $500 to $2,500. It looks natural and elegant, and koi fish love to swim in the water currents waterfalls create.
Water fountain
You can use a water fountain to replace a waterfall or to complete the aeration system into a larger pond. The typical water fountain cost ranges from $1,100 to $4,300.
Pond plants
Aquatic plants cost $4 to $45 and can offer protective shade when building ponds in a sunny location. Make sure you choose only plants that are not toxic to fish.
Cost of installing a koi pond by location
Labor rates and materials costs vary by location. You will pay more to install a koi pond in cities like New York, Los Angeles, or Boston, and less in places like Dallas or Kansas City. Fees are also lower in smaller towns and rural areas.
FAQ
As a rule of thumb, you should have 4 fish or less per 1,000 gallons of water. This prevents overcrowding and allows you to grow healthy, stress-free koi.
Yes, you can, but it’s not recommended. Building a pond to grow fish is more complicated than a simple garden pond for decorative purposes. Too many things can go wrong, making pond maintenance difficult and exposing your fish to disease and accidents. We recommend consulting a professional pond builder before starting anything on your own.
A custom-made koi pond can increase your property value significantly. Still, this depends on supply and demand. Only some people enjoy caring for fish, while others might prefer a swimming pool or a simple garden pond.
Fishing ponds cost $8,625 to $52,500. They are built for hatchery and yearly harvestry and are larger than koi ponds. Most have at least half an acre and a depth of 6 to 12 feet.
To install an in-ground koi pond, a landscaping company excavates your yard, then lies down a flexible liner or pours a concrete one. For an above-ground pond, a rigid prefabricated liner is installed.
The average cost to install a pond is $3,675 – $14,500. With a typical price range of $5,100 to $15,875, koi ponds cost more because they are ecosystem ponds. They require more complex equipment to maintain water quality, and koi fish raise the total price.
Final thoughts
Watching fish swim is calming and soothing and can help you relax after a busy day. You can enjoy this experience in your own yard by building a koi pond with an average investment of $5,100 to $15,875.
The project also increases your home value, especially if you go for a concrete pond. Contact a contractor in your area and find out how much it would cost to have your own pond with playful koi and crystal clear water.
Note: Lawn Love may get a referral fee for matching you with contractors in your area.
Main Photo by: Michael Rivera – Wikimedia Commons – CC BY-SA 3.0
