TOTO K300 vs S300e: Is it Worth Paying Extra?

Today’s article looks at the differences between the S300e and K300. Is one better? And if one is more expensive, do the extra features warrant the added cost? 

When comparing the TOTO S300e and K300, the K300 is the better option, since it offers most of the same features at about half the price. This is also true for the SW3036R, the K300 version with EWATER+. The only other notable difference is that the S300e is available in round.

Best Option for the Money
TOTO K300 Washlet

I can’t recommend this bidet enough. It offers way more features than most bidets at this price point.

Adjustable Features:

  • Water Temp
  • Water Pressure
  • Heated Seat
  • Dryer Temp
  • Nozzle Position
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If you have an elongated toilet, I’d recommend the K300 with EWATER+. If your toilet has a round bowl, I’d recommend the TOTO S350e Washlet SW583 in favor of the S300e, since it’s also available in round, costs less, and has more features (also available on Amazon).

You can save a little money by going with the K300 version without EWATER+ (SW3036), but the added cost is worth it since EWATER+ is one of the key features that set TOTO bidets apart from the rest. 

So, let’s get into it. 

TOTO K300 vs S300e: Quick Summary Table 

Feature(s)TOTO S300eTOTO K300
Endless Warm Water
(Tankless Heater)
Bowl ShapeElongated and RoundElongated Only
Warm Air Dryer 5 Temp Settings3 Temp Settings
Heated Seat5 Temp Settings3 Temp Settings
Self-Cleaning NozzleAutomaticAutomatic
Self-Sanitizing Nozzle
All VersionsWith SKU SW3036R
Wand Positions55
Wand MaterialPlasticPlastic
Wireless Remote YY
Wall-Mounted Cradle for
Wireless Remote
Night LightNN
Auto-Open/Close Seat and LidNN
Slow-Close Seat and LidYY
Auto Flush
Before Use
Self-Cleaning Bowl
Nozzle OscillationYY
Nozzle Pulse/Massage YY
Personal Settings2 User Presets2 User Presets
Air DeodorizerYY
Energy Saver Functions3 Eco Modes4 Eco Modes
Water Temp86 to 104 °F95 to 104 °F
Water Pressure0.07-0.11 gal/min or
0.27-0.43 L/min
0.07-0.11 gal/min or
0.27-0.43 L/min
NozzleSingle, PlasticSingle, Plastic
AestheticsClassic Design OnlyContemporary Design Only
(Rear Height)
3.84″ or 9.75cm5.2″ or 13.1cm

The TOTO K300 Washlet 

TOTO SW3036R#01 WASHLET K300 Electronic Bidet Toilet Seat, Cotton White

First up, is the K300 Washlet with EWATER+ (also available here).

The K300 SW3036#01 is the version without EWATER+ (Amazon link). It can often be found for less.

I’ll say right out, the K300 is the one I’d go with. It’s my favorite TOTO bidet because it’s the least expensive TOTO that offers endless warm water via a tankless heating system. 

It also has a wireless remote, unlike the C2, C100, and A100.  

I.e., it has 90% of the features on offer by the luxury TOTO toilets (S300e through S550e) but is available at about half the price.  

Like the luxury TOTOs, it has PREMIST technology, adjustable everything, a warm air dryer, and an air deodorizer.

The K300 is more of a middle-of-the-road or “premium” option by TOTO standards but would be considered a luxury bidet by other manufacturers. The SW3036R version has a self-sanitizing wand (via EWATER+) when most bidet wands clean with regular tap water. 


  • Cheaper than the S300e despite offering roughly the same features. 
  • Compared to the best TOTO bidets (the S350e and S550e) the K300 has all but three features, while costing about half as much. 
  • The K300 is a better-looking bidet than the S300e (if that matters) with a more modern design. 


  • It’s only available for elongated toilets. 
  • The version with EWATER+ (the SW3036R) sometimes costs extra. It really depends on the timing and retailer.  

The TOTO Washlet S300e

TOTO SW573#01 S300E Electronic Bidet Toilet Cleansing, Instantaneous Water, EWATER Deodorizer, Warm Air Dryer, and Heated Seat, Round, Cotton White

Next up, is the TOTO S300e Washlet (Amazon link).

There have been several versions of the S300e over time, but right now SKU SW574T20 is the only one on the market that I’ve run into recently.  

It’s a great bidet, there’s no doubt about it. It has all the bells and whistles of the S500e: tankless water heater for endless warm water, EWATER+ and PREMIST technologies, an air deodorizer, warm air dryer, and Wide Front wash mode.

But I remain confused about how these bidets are priced. For the same price, you can get the S350e or S550e.


  • One of TOTO’s luxury bidets. 
  • A couple of extra features compared to the K300 like an after-mist function and Front Wide spray mode. 


  • It’s about the same price as the S350e and S550e despite offering fewer features. This is the nail in the coffin, IMO. For the same price, you could get the S550e, the best TOTO bidet on the market. 
  • Almost twice the cost of the K300 despite only offering very little extra.  
  • Older, less modern look.  
  • If you have a round toilet, you’re better off going with the S350e, since it offers more features while costing the same. 

The Main Differences 

The K300 is More Aesthetic and Designed for Modern Bathrooms 

If you look at the above pictures, you’ll see that the S300e has a more antiquated look, with the divot that runs around the outer edge of the lid. It’s less streamlined and looks more like a bidet than a regular toilet seat. 

The design of the K300 is more minimalistic. 

TOTO makes two styles of bidets looks-wise, one they call “Classic” and the other “Contemporary”. The S500e and S550e are available in both, while the S300e and S350e are only available in Classic. 

The K300 only comes in Contemporary. 

The S300e Is Available for Round Toilets

If you have a round toilet, you won’t be able to use the K300.

Round toilet bowls are a couple of inches shorter compared to elongated toilets and have less of an oval shape.

Hence, putting an elongated bidet on a round toilet would result in significant overhang.

Again, I’d recommend the TOTO S350e Washlet for round bowls (Amazon link),

The K300 Lacks an After-Mist Function 

A seat sensor detects when you sit down and sprays the toilet bowl. This keeps waste from sticking to the toilet.  

The S300e through S550e bidets perform an after-mist by spritzing the bowl once more when the user is finished.  

TOTO claims that the PREMIST technology cleans bowls 80% better, but I’m not sure how essential the after-mist function is.  

I have a TOTO C2 which only pre-mists the bowl so I can’t speak from experience. I can say that the PREMIST works wonders, and I can’t tell you the last time I had to manually clean the toilet bowl. 

The S300e Has a Wide Front Spray Mode 

The S300e through S550e bidets have a wide frontal spray mode for soft feminine cleansing that hits a wider area.  

You don’t need the feature to get soft frontal cleansing, but having a wider spray means there’s less of a need to adjust body positioning to get good coverage. 

Other Minor Differences  

Aside from the above, there’s not a huge difference between the two bidets. But there are a few minor differences. 

For example, the K300 has 3 heat settings for the heated seat, water, and warm air dryer, while the S300e has 5

The K300 has an extra Eco mode that turns the heated seat off during periods of infrequent use, whereas the S300e simply turns the seat temp down.  

It doesn’t look like the K300 has a cradle with the wireless remote. Cradles are typically magnetic and meant for housing the remote between uses. 

The K300 and S300e vs Top-Tier Luxury Models (S350e and S550e)

The two bidets are missing a couple of features offered by the S350e and S550e.

Examples include: 

  • Incompatible with Auto-Flush technology. This only applies to folks with Auto-Flush-enabled TOTO toilets. Only the S500e and S550e bidets have this capability. 
  • Neither bidet has a nightlight. A nightlight illuminates the bowl making bathroom navigation easier. The only TOTO bidets to have nightlights are the S350e and S550e. I’m not sure why that is, given that the feature is pretty common even with entry-level bidets. But the feature is hard to come by with TOTO units.  
  • No auto open-close seats/lids with either bidet. The S350e and S550e allow the user to open the bidet seat and lid via remote control. All other TOTO bidets have slow-close seats and lids. 

Both Bidets Have These Awesome Features 

Endless Warm Water with Adjustable Temperature 

  • Both have instantaneous water heaters for endless warm water. 
  • Water temp is adjustable between 86° F and 104° F for the S300e and between 95° F and 104° F for the K300. 

Adjustable Water Pressure

  • Adjustable pressure w/5 settings.  
  • Both offer decent water pressure with an output of 0.07 to 0.11 gal (or 0.27 – 0.43 L) per minute.  
  • There’s no strong or turbo mode with TOTO bidets, in general. 

Self-Cleaning Nozzles That Sanitize with EWATER+  

Any time you use the bidet, there’s a chance the cleaning wand will get soiled. So, it’s nice to have self-cleaning nozzles, and better yet, nozzles that self-sanitize. 

The K300 and S300e have automatic, self-cleaning wands. This means the nozzles self-rinse automatically before and after each use. So, no need to remember to use the function. 

You can also perform the nozzle-clean function on demand. 

What makes TOTO bidets stand out is the use of EWATER+, an electrolyte solution that forms antimicrobial sodium hypochlorite, or NaOCl, a chemical used in water treatment.

Aside from disinfecting, EWATER+ creates a slippery surface on the wand preventing waste from sticking. 

PREMIST Keeps the Toilet Bowl Clean 

The PREMIST function sprays water into the bowl which helps keep waste from sticking, helping the toilet stay clean for longer.  

As mentioned, the S300e sprays the bowl before and after use, but both have the PREMIST function that prevents waste from sticking to the toilet after BMs and urination.

Other Luxury Features (Warm Air Dryer, Air Deodorizer, Heated Seat, Wireless Remote) 

  • Both come with a warm air dryer, with adjustable temperature.  
  • Sleek, illuminated wireless remote. The remote with the S300e comes with a cradle. 
  • Two user presets for saving personal preferences. 
  • Built-in air deodorizer that uses carbon filters to eliminate embarrassing bathroom odors. 
  • Heated seat with temperature adjustable from 82 to 97 °F.  
  • Convenient, quick-release mechanism for easy bidet removal and cleaning. 
  • Soft-Close, slam-free seat and lid to save wear and tear over time. 

Spray Capability  

  • Both bidets come with a dual-action spray wand that’s adjustable to 5 positions for max accuracy.  
  • Both come with Rear (regular), Rear Soft, and standard Front cleansing. The S300e has a Front Wide cleaning mode.   
  • Both have an oscillating spray mode. To “oscillate” means to move back and forth or side-to-side like a sprinkler. With the oscillating spray mode activated, the nozzle moves back and forth to clean more effectively and hit a wider area. 
  • Finally, both bidets come with a massage/pulse spray setting that rotates hard and soft pressure for a massage effect. 

Other Great Features  

  • Both bidets have a safety sensor that prevents the bidet from operating when the toilet is unoccupied. This helps prevent unwanted surprises.  
  • Both bidets have Eco modes that turn energy-zapping components down to their lowest setting during periods of infrequent toilet use. 

TOTO S300e vs k300: Bottom Line 

So, there you have it. 

If you have an elongated toilet, go with the K300 with EWATER+. If you have a round toilet go with the S350e SW583. If you want high-end luxury features like the auto-open/close seat/lid and bowl-illuminating nightlight, go with the S350e or S550e.

The biggest difference between the TOTO K300 and S300e is the price since the two bidets offer most of the same features. The K300 offers 99% of the S300e features around half the price. For the price of the S300e, you may as well go with the S550e or S350e.

Sure, another difference is that the S300e is available for round toilets. But again, the S350e is too, and it’s about the same price (sometimes cheaper) while offering more features. 

That’s it for now. Thanks for reading. 

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