A DIY cold plunge sounds like a cheap weekend project, and sometimes it is. A chest freezer build can land well under $400 in parts, while a stock tank with a real chiller costs more than most people expect. I priced both builds from listings I actually opened, and I'm going to show the line items so you can redo the math yourself. I also cover what I could not verify, because a few parts of this topic are murky.
One thing up front. I haven't built any of these, and I'm not an electrician. This page is a buyer's guide: prices, specs the makers publish, and cautions from safety organizations. It is not a wiring tutorial, and I won't write one.
What a DIY cold plunge actually is
There are two common ways to make a cold plunge at home. The first is a chest freezer cold plunge: you fill a converted freezer with water and let its compressor chill it, usually with an external temperature controller. The second is a stock tank cold plunge, where a plastic livestock tank holds the water and a separate chiller and pump cool it.
Both are variations on the same idea. You take parts that were never designed for a person to sit in, and you add cold water. That's the whole risk and the whole appeal. Cheap parts, no brand markup, but also no safety listing for the finished thing.
Sun Home Saunas says plainly that chest freezers are not UL- or CE-listed for human immersion. That's a retailer with a tub to sell, so weigh it accordingly, but I think the point stands on its own. A freezer wasn't built to hold water with a person in it.
The parts list, with prices I could find
Here are the line items from listings I opened. Prices move around, so treat these as a snapshot from October 2026.
| Part | Listing I opened | Price |
|---|---|---|
| 7 cu ft chest freezer | Frigidaire EFRF7003 on Walmart | $238.00 (marked down from $449.99) |
| 100 gal stock tank | Rubbermaid FG424288BLA on Walmart | $98.32 |
| 1/2 HP water chiller | EcoPlus on Hydrobuilder | $1,386.11 |
| Circulation pump, 1,083 GPH | EcoPlus Eco 1056 on Hydrobuilder | $99.45 |
| Temperature controller | Inkbird ITC-308S | $36.99 |
| Cartridge filter pump, 1,500 GPH | Intex Krystal Clear C1500 on Walmart | $84.99 |
A few honest caveats on that table. The freezer page shows a $238 price, but the "marked down from $449.99" wording was attached to the black granite model, and I couldn't tell for certain which finish the $238 applies to. The 530 GPH Intex pump I actually wanted to price was out of stock with no price shown, so I used the larger 1,500 GPH version that did have one. A bigger pump than you need isn't a disaster, but it isn't a clean comparison either.
I left out sealant, a thermometer, hoses, fittings, a cover and any sanitizer. I found no listing I could cite for them, and I won't guess.
Two builds, added up
My arithmetic, using only the table above:
- Chest freezer build: $238.00 freezer + $36.99 controller + $84.99 filter pump = $359.98
- Stock tank with chiller: $98.32 tank + $1,386.11 chiller + $99.45 pump + $84.99 filter pump = $1,668.87
Neither total includes the missing items above, so both are floors. For context, other writers put a freezer conversion at $400 to $1,100 or $500 to $1,200, and a stock tank with a chiller at $600 to $1,500. My freezer total sits below those ranges because I counted fewer parts. My chiller total sits above the top of one range because the EcoPlus unit I found is a pricey one. A cheaper chiller exists, I just didn't open a listing for one.
That second number matters if you came here to save money. A DIY cold plunge with chiller at $1,669 is still a long way under a finished tub, but it's no longer a bargain bin project.
Chest freezer cold plunge: where it works and where it doesn't
The freezer route is the cheapest because the cooling hardware is already inside the box. A controller sits between the wall and the freezer so the compressor cycles around your target temperature. The Inkbird lists a control range of -58 to 210 degrees F and a 10A output rating.
The trouble is fit and function. The Costco listing gives the exterior of a 7 cu ft Frigidaire as 33.5 by 23 by 34 inches. That's the outside. I couldn't find an interior dimension on any page I opened, and I'd want that number before I trusted a freezer to hold a grown adult. IceTubs makes a related point: if the freezer is hard to climb into when it's empty, it will be worse wet, cold and full of water.
Then there's the other side of the bargain. IceTubs says a chest freezer build isn't the most beginner-friendly path, and Sun Home describes the DIY water as getting cloudy within days and needing 30 to 60 minutes of upkeep a week. Both are vendors with a stake in the answer. Still, I haven't found a credible source arguing the opposite.
Stock tank cold plunge: more space, more parts
A stock tank cold plunge gives you room. The Rubbermaid tank I opened is listed at 100 gallons and 53 by 31 by 25 inches, with a drain plug. For comparison, The Plunge lists 66-5/8 by 31-1/2 by 26 inches and 105 gallons, and says it fits people up to 6 feet 8 inches. So a 100 gallon tank is a bit shorter than the finished tub. Taller people should check this before buying.
The chiller I priced lists a maximum tank size of 100 gallons, 510 watts, 4.4 amps on 120V, and a one-year warranty. It recommends the Eco 1056 pump, which lists 89 watts and a one-year warranty. Notice that the tank and the chiller's ceiling match exactly. If you wanted a bigger tank, you'd need a bigger chiller and a new price.
One more thing to watch: the pump page says it must never run without enough water, with a stated minimum depth of 6 inches. A pump that sits in a half-drained tub is a dead pump.
Electrical cautions from people who study this
This is the section I'd read twice. Water and electricity is the whole reason an unlisted DIY cold plunge deserves respect.
The Electrical Safety Foundation International recommends a ground fault circuit interrupter (GFCI) for electrical devices used outside, notes that portable GFCIs cost $12 to $30, and says to keep devices and cords at least 10 feet from pools and spas. It also advises having an electrician inspect and upgrade a pool, spa or hot tub to local codes and the National Electrical Code. The Consumer Product Safety Commission gives the same electrician advice and warns that stray current can incapacitate a person, turning rescuers into secondary victims.
Those pages are about pools and spas, not cold plunges, so I'm borrowing the principle rather than quoting a rule that applies to your tub. A 10-foot clearance, for example, is plainly impossible for a plunge you're sitting in. That's the point: a setup that can't meet the usual spacing needs a professional to look at it.
IceTubs adds the practical version: no damaged cords, no plugs near wet floors, no improvised wiring, and don't get in if anything about the electrical setup feels uncertain. Sun Home calls a GFCI-protected circuit non-negotiable.
My decision rule is simple. If you can't say exactly where every cord goes, which outlet is GFCI protected, and who inspected it, don't get in the water. Hire a licensed electrician before the first plunge, not after the first scare. The chiller I priced draws 4.4 amps by its own listing, and The Plunge asks for a dedicated 120V 15A circuit. Whether your outlet can carry that is an electrician's question.
What it costs to run
The Energy Information Administration projects an average residential price of 18.2 cents per kWh for 2026. My arithmetic for the stock tank build, with two assumptions I'm making up for illustration: the chiller runs 8 hours a day and the circulation pump runs 24 hours.
- Chiller: 0.510 kW x 8 h x 30 days = 122.4 kWh, times $0.182 = about $22.28 a month
- Pump: 0.089 kW x 24 h x 30 days = 64.1 kWh, times $0.182 = about $11.66 a month
- Total: about $33.94 a month
Your chiller may run more or less than 8 hours, especially in a hot garage or summer yard. I couldn't verify a freezer's real draw because the listings I opened don't state it. Sun Home gives $11 to $16 a month for DIY and $20 to $35 for purpose-built, but doesn't show its math, so I'd use it as a rough check only.
DIY versus buying a tub
Sun Home puts purpose-built tubs at $3,000 to $7,000. The Plunge, one example, lists $6,790, an included chiller that can reach 37 degrees F, six starter filters, and a one-year warranty. Against my $1,668.87 chiller build, the gap is $6,790 minus $1,668.87, or $5,121.13 (my arithmetic).
That's real money. But the tub comes with built-in filtration and one seller to call, and Sun Home says purpose-built units carry safety certifications. The DIY build comes with a warranty split across several makers: one year on the chiller, one year on the pump, and two years on the Intex pump. If something fails, you're the one figuring out which part.
Sun Home's own verdict is that DIY suits people plunging once or twice a week who are comfortable with electrical work, and that tubs fit 4 to 7 sessions a week better. I'd add that the "comfortable with electrical work" part should mean you have an electrician in your phone, not that you watched a video.
What I could not verify
- Interior dimensions of any chest freezer, which decide whether an adult fits.
- Actual power draw of a freezer running as a cold plunge.
- Sealant, thermometer, hose and fitting costs.
- Whether a freezer's warranty survives conversion. I'd assume it doesn't, but I found no page that says so.
- Any independent lab data on DIY water quality. Sun Home's claims come from a seller.
Frequently asked questions
Is a DIY cold plunge safe?
It can be made safer, but it isn't certified. Freezers aren't listed for human immersion, so the electrical setup is on you. Use GFCI protection and have an electrician inspect it. Also talk to a doctor first if you have heart disease or high blood pressure.
How much does it cost to make a cold plunge at home?
From my sourced parts, about $360 for a freezer build and about $1,669 for a stock tank with a chiller, both before sealant, thermometer and fittings. Other writers quote $400 to $1,100 for freezers and $600 to $1,500 for stock tanks with chillers.
Can I just use a stock tank and ice?
You can, and plenty of people do. Science Insights puts a basic ice bath at $50 to $300 up front plus $20 to $60 a month in ice. I didn't verify ice pricing myself, so check your local bag price.
Do I need a chiller?
Not for an occasional ice bath. Past a couple of sessions a week, hauling ice gets old and a chiller starts making sense. The one I priced is rated for tanks up to 100 gallons.
How long can I stay in?
I won't give a dose. Research on benefits is mixed and limited, and Science Insights lists conditions such as heart disease, high blood pressure and Raynaud's as reasons to avoid plunging. Ask your doctor.
What I would do
If you plunge once or twice a week and want to spend as little as possible, I'd start with a stock tank and ice. It has no mains power in the water at all, which removes the biggest risk on this page. Buy the tank first, see whether you keep using it for a month or two, and only then decide on a chiller.
If you already know you'll plunge often, I'd skip the DIY cold plunge with chiller and price a finished tub, or at minimum pay an electrician to set up a dedicated GFCI outlet. A DIY build that costs $1,669 plus electrician time narrows the saving a lot, and you carry the warranty and sanitation headaches yourself. I'd only build a chest freezer version if I'd confirmed the interior size, had the circuit inspected, and accepted the weekly upkeep.
If you decide to buy instead, see cold plunge cost for price tiers and cold plunge with chiller for specific tubs. The power draw of a home-built chiller is estimated in cold plunge electricity cost.