If you're standing in your backyard visualizing a steaming spa, the big question is usually how much do hot tubs cost per month to actually keep running. It's one thing to swipe your card for the initial purchase, but it's the ongoing "membership fee" to the relaxation club that most people worry about. Honestly, the answer isn't a one-size-fits-all number, but for most modern setups, you're looking at somewhere between $30 and $100 a month.
That might sound like a wide range, but there are a lot of moving parts—literally and figuratively. From the climate you live in to how often you're cranking up the jets, your monthly bill can fluctuate. Let's break down the nitty-gritty of where that money actually goes so you don't get hit with any surprises when the utility bill arrives.
The biggest slice of the pie: Electricity
By far, the most significant chunk of your monthly cost is going to be power. You're essentially keeping a massive thermos of water at 100-plus degrees 24/7. That takes juice.
How much electricity a hot tub uses depends heavily on the quality of the tub's insulation. If you bought a high-end model, it likely has full-foam insulation. This stuff is a lifesaver for your wallet because it traps the heat inside the cabinet, meaning the heater doesn't have to kick on nearly as often. On the flip side, if you went with a budget-friendly or inflatable model, you might save money upfront, but you'll probably pay for it in your monthly bill. Inflatables are notorious for losing heat through their walls, which can cause your electric bill to jump by $50 or more just on its own.
Your local climate plays a massive role too. If you're living in a place where the winters are brutal, your heater is going to be working overtime. A hot tub in Minnesota in January is going to cost way more to run than one in Arizona. Most manufacturers estimate costs based on an average ambient temperature of about 60°F, so if you're living in the frozen north, take those "estimated monthly costs" on the showroom floor with a grain of salt.
Chemicals and water testing
You can't just fill a tub with water and leave it. Well, you could, but you'd basically be inviting a science experiment to live in your backyard. To keep the water clear and safe, you need a regular cocktail of chemicals.
We're talking about sanitizers (like chlorine or bromine), pH balancers, alkalinity increasers, and the occasional "shock" treatment. On average, you're probably looking at about $15 to $25 a month for these supplies.
It sounds like a chore, but once you get into a rhythm, it only takes a few minutes a week. Some people opt for salt water systems or UV/Ozone purifiers. These systems cost more to install initially, but they can actually lower your monthly chemical spend because they do a lot of the heavy lifting for you. Regardless of the system, you'll still need to test the water regularly to make sure everything is in balance.
Water usage and drainage
Believe it or not, the actual water isn't a huge expense. Even if you have a 400-gallon tub, you aren't filling it every day. Most experts recommend draining and refilling your hot tub every three to four months.
Depending on where you live and your local water rates, filling a hot tub usually costs less than $10. If you spread that out over the three or four months the water lasts, it's a negligible monthly cost—maybe $2 or $3.
However, you do lose some water to evaporation and "splash-out" (especially if you have kids who think the hot tub is a swimming pool). You'll occasionally need to top it off with a garden hose, but again, we're talking about pennies here.
Filters and hardware upkeep
Think of your hot tub filter like the oil filter in your car. It's working hard to catch hair, oils, and lotion so the water stays crisp. You should be rinsing your filter every couple of weeks, but eventually, it'll just get too gunked up to work.
Most filters need to be replaced every year or two, and they usually cost between $30 and $60. If we bake that into your monthly budget, you're adding another $3 to $5 a month.
Then there's the "just in case" fund. Hot tubs have pumps, heaters, and control boards. While a new tub should be under warranty for several years, older tubs might need a part replaced here and there. It's always a good idea to mentally set aside a few dollars a month for future repairs so a leaky seal doesn't ruin your weekend.
The impact of your cover
If there's one thing that can drastically change how much do hot tubs cost per month, it's the cover. About 90% of a hot tub's heat escapes through the surface of the water. A thick, well-fitting, insulated cover acts like a lid on a pot of boiling water—it keeps the heat exactly where you want it.
If your cover is old, heavy (waterlogged), or has gaps around the edges, your heater is basically fighting a losing battle against the cold air. A heavy cover means the internal foam has absorbed water, and instead of insulating, it's actually pulling heat away from the water. Replacing a bad cover might cost $400, but it can pay for itself in energy savings in less than a year.
Tips to keep the bill low
If you're looking at these numbers and feeling a bit of "bill-fright," don't worry. There are ways to keep the costs on the lower end of the spectrum:
- Drop the temp: You don't need the water at 104°F if you aren't using it. Dropping it to 98°F or 100°F when it's idle can save a surprising amount of energy.
- Check your jets: Make sure the air valves are closed when you aren't in the tub. If they're left open, cold air gets sucked into the water, cooling it down faster.
- Use a thermal blanket: These are thin floating sheets that sit on the water's surface under your main cover. They add an extra layer of protection against evaporation and heat loss.
- Time your heating: Some modern tubs have "economy modes" that allow you to program the heater to run during off-peak electricity hours.
Is it worth it?
When you add it all up—the electricity, the chemicals, the filters, and the occasional water top-off—the average person is spending about $1.50 to $2.50 a day to run their hot tub.
For a lot of people, that's less than the price of a cup of coffee. When you weigh that against the stress relief, the better sleep, and the fact that you have a private spa in your backyard, most owners find the monthly cost totally manageable.
The key is to invest in quality from the start. A well-insulated, high-quality tub might cost more at the dealership, but it'll reward you with a much lower monthly bill for years to come. If you go cheap on the front end, just be prepared for the electric company to become your new best friend.
Ultimately, knowing how much do hot tubs cost per month helps you enjoy those bubbles without stressing about the math. It's a luxury, sure, but in the grand scheme of home expenses, it's one of the more affordable ways to turn your home into a sanctuary. Just keep that cover on tight and keep your chemicals balanced, and you'll be golden.