A hot tub and a swim spa look similar in marketing photos but serve different purposes. A hot tub is a small heated soaking pool with massage jets, designed for relaxation at 38 to 40 degrees C. A swim spa is a larger unit with a current generator that lets you swim in place against the flow, designed for exercise at 28 to 35 degrees C. Some swim spas include a separate hot tub section, giving you both. The right choice depends on what you actually want to do most often, the space available, and the budget over a 10 to 20 year ownership horizon. This guide breaks down the engineering, costs, and ownership tradeoffs.
How hot tubs work
A hot tub is a self-contained acrylic or rotomolded shell, typically 2 to 2.5 meters across, 1 meter deep, holding 800 to 2000 liters of water. The equipment bay (motor, heater, filter, control panel) sits in a compartment built into the cabinet around the shell.
Heating: a 4 to 6 kW electric resistance heater warms the water and maintains temperature. The standard hot tub temperature is 38 to 40 degrees C (US health code caps residential at 40 degrees C). The heater cycles on for 30 to 60 minutes at a time, several times a day, to replace heat lost through the cover and shell.
Jets: typical residential hot tubs have 20 to 80 jets, powered by one or two pumps. Pumps run at 1 to 3 HP and produce 80 to 200 LPM of flow at the jet head. Jet types include directional jets (focused stream), rotational jets (massaging tornado pattern), and adjustable jets. Premium tubs (Hot Spring, Bullfrog) tune jet positioning to specific muscle groups (lower back, calves, neck, shoulders).
Filtration: a filter cartridge cleans water as the circulation pump runs. Most hot tubs filter the entire water volume 2 to 4 times per day at low pump speed. Sanitizer (chlorine, bromine, or ozone with mineral system) maintains water clarity.
Cover: an insulated foam cover with vinyl exterior locks in heat when the tub is not in use. The R-value of the cover (R-12 to R-18 for quality covers) determines how much heat is lost overnight and how often the heater cycles. A quality cover is the single largest factor in electricity cost.
Hot tub cost in 2026: 4000 to 8000 dollars for entry level acrylic, 8000 to 14000 dollars for mid-range, 14000 to 25000 dollars for premium. Inflatable hot tubs run 400 to 1200 dollars but are a different category of product.
How swim spas work
A swim spa is a longer, deeper version of a hot tub built around a swimming current. Typical dimensions are 4 to 6.5 meters long, 2.3 meters wide, 1.4 meters deep, holding 4000 to 7000 liters.
The current generator is the defining feature. Three current technologies are common:
Jet-driven (most consumer swim spas): one or two large jets at one end produce a flow stream. Adjustable from gentle to vigorous. The current is somewhat turbulent and harder to swim against in a clean stroke. Adequate for casual exercise. Power: 3 to 6 kW pump load.
Propeller-driven (Endless Pools, premium swim spas): a large propeller behind a grille produces a smooth, even current similar to swimming in a river. The current is uniform from top to bottom of the swim channel. Premium swim spas with propeller systems can simulate a 1:30 per 100 meters pace, which is competitive swimmer speed. Power: 2 to 4 kW.
Hydraulic paddlewheel (SwimEx, some commercial units): an underwater paddlewheel creates a deep, smooth current that simulates open water swimming most closely. Found mostly in commercial and therapy installations. Highest cost.
Many swim spas include a separate hot tub section at one end, with jets and a higher temperature setpoint. The two zones can be temperature-controlled independently in some models.
Swim spa cost in 2026: 15000 to 25000 dollars for entry level (small, jet-driven, simple controls), 25000 to 40000 dollars for mid-range (longer, better jets, propeller in some models), 40000 to 80000 dollars for premium (Endless Pools, SwimEx, top-tier with propeller).
Heating costs over a year
Hot tub (1500 liter, 39 degrees C, quality cover, R-15 insulation): 15 to 25 kWh per day, 5500 to 9000 kWh per year. At 0.15 dollars per kWh: 825 to 1350 dollars annually.
Hot tub in cold climate or with poor insulation: can exceed 12000 kWh per year, 1800 dollars annually.
Swim spa (5000 liter, 32 degrees C swim mode, plus separate hot tub at 39): 25 to 50 kWh per day depending on use of swim current. Annual energy: 9000 to 18000 kWh, costing 1350 to 2700 dollars at 0.15 per kWh.
Lowering temperatures, using the cover religiously, and adding insulation around the cabinet reduce these numbers by 20 to 40 percent.
For cold climate installations, factor in higher heater run-time during winter. A hot tub in Minneapolis costs roughly twice what one in San Diego costs to run.
Maintenance burden
Hot tub: weekly water testing and chemical balance (5 minutes), monthly filter rinse (10 minutes), quarterly filter chemical clean (30 minutes), quarterly drain and refill (1 to 2 hours). Annual cover inspection and treatment. Total: about 5 to 10 hours per year, plus 200 to 400 dollars in chemicals.
Swim spa: similar weekly chemistry but with twice the water volume to maintain. Monthly filter clean (15 minutes for two filters). Quarterly drain and refill (2 to 3 hours). Annual cover and current system inspection. Total: 8 to 15 hours per year, 300 to 600 dollars in chemicals.
Saltwater conversion is available for both formats and reduces chemical labor by 30 to 50 percent.
Space and installation
Hot tub: typical footprint 2.5 by 2.5 meters, plus 60 cm clearance around. So 3.7 by 3.7 meters installation area. Many decks and patios can fit one with minimal modification. Concrete pad or reinforced deck required (1500 to 3000 kg loaded weight). Electrical: dedicated 240V 50 amp circuit, professionally installed.
Swim spa: footprint up to 7 by 3.5 meters for a 6 meter unit with service access. Often requires excavation or a poured concrete pad sized for the larger weight (1800 to 3200 kg dry, plus 4000 to 7000 kg of water). Electrical: 240V 50 to 60 amp circuit, sometimes two circuits if hot tub section has separate heating.
Delivery is a challenge for swim spas. The unit must be craned into position or rolled on dollies along a wide-enough access path. Verify access before ordering.
Use case fit
Hot tub fits: evening relaxation, partner or family soaks, post-workout recovery, social entertaining for 4 to 8 people, year round use in any climate.
Swim spa fits: regular cardiovascular exercise, year round swimming in cold climates, physical therapy and rehabilitation, families wanting both swim and soak in one unit, properties where a full in-ground pool will not fit.
Skip hot tub if: you swim laps for exercise (it cannot do this), you live in a hot climate and rarely want hot water relaxation (a pool serves better).
Skip swim spa if: you would not actually swim regularly (the swim feature is the entire premium versus a hot tub), the budget is tight (a separate hot tub plus pool membership is cheaper), or installation logistics rule out the size.
Combined recommendation
For relaxation, social use, and post-exercise recovery, choose a 5 to 7 person hot tub in the 8000 to 14000 dollar range (Hot Spring Aria, Bullfrog A8, Sundance Cameo). Quality insulation and a tight cover keep electricity costs manageable.
For exercise plus relaxation in one unit, choose a swim spa with a propeller-driven current system and a separate hot tub section. Budget 30000 to 50000 dollars (Endless Pools E-Series, Hydropool Self-Cleaning).
For occasional use, low commitment, or rental properties, an inflatable hot tub at 600 to 1000 dollars is the right call.
For dedicated lap swimmers in a cold climate, a swim spa is the most practical year round option. For lap swimming in a warm climate, a real in-ground pool with a heater is cheaper to run.
For more pool guidance see our pool salt vs chlorine guide and our pool pump types guide. Review methodology at /methodology.
Frequently asked questions
Can you really swim in place in a swim spa?+
Yes, but the swimming experience depends on the current generation system. Propeller-driven current systems (Endless Pools, SwimEx) produce a smooth, even current that works for serious lap swimming. Jet-driven systems (most consumer swim spas) produce a turbulent current that works for casual exercise but is harder to swim against cleanly. Current speed is adjustable from a gentle resistance to about 3 minutes per 100 meters pace (sub-2 minute on premium propeller systems).
How much electricity does a hot tub use?+
A 240V hot tub heater uses 4 to 6 kW while heating, and a typical hot tub heats for 4 to 8 hours per day to maintain temperature. Total daily electricity is 15 to 30 kWh, or 80 to 130 dollars per month at 0.15 dollars per kWh. Cold climates and uninsulated covers push this higher. Quality insulation, a tight cover, and lowering temperature when not in use can drop monthly cost to 40 to 70 dollars.
How much space does a swim spa need?+
A swim spa is typically 4 to 6.5 meters long, 2.3 meters wide, and 1.4 meters tall. Allow 0.6 meters around the perimeter for service access. So the installation footprint is around 7 by 3.5 meters minimum. Most swim spas weigh 1800 to 3200 kg dry and need a reinforced concrete pad. Many homes can fit a swim spa where they could not fit an in-ground pool.
Are inflatable hot tubs worth buying?+
Inflatable hot tubs (Lay-Z-Spa, Intex PureSpa, Coleman SaluSpa) cost 400 to 1200 dollars and work as expected for 1 to 3 years of moderate use. They are reasonable for renters, occasional users, and seasonal climates. The downsides are weaker jet pressure, electric heater inefficiency, vinyl liner wear, and higher running costs per hour. They are not a substitute for a proper hot tub if you plan 5 plus years of regular use.
How long does a hot tub last?+
Quality acrylic-shelled hot tubs (Hot Spring, Jacuzzi, Sundance, Bullfrog) last 15 to 25 years before the shell or plumbing requires major repair. Mid-range tubs (Caldera, Marquis, Coleman Spas) last 10 to 18 years. Budget tubs from big-box stores last 5 to 10 years. Rotomolded plastic spas (Freeflow Spas) are a value option that lasts 8 to 15 years. Inflatable spas last 1 to 3 years of regular use.
