Thermos Stainless King Travel Mug Review

This durable travel mug will keep your coffee hot for hours

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Thermos Stainless King Travel Mug

Thermos Stainless King Travel Mug

 The Spruce Eats / Rebekah Joan

What We Like
  • Keeps drinks hot/cold for hours

  • Comfortable to hold

  • Lid seals tightly

What We Don't Like
  • Lid is hard to clean

  • Doesn’t fit in all car cup holders

If you’re looking for a heavy-duty travel cup that will keep your morning coffee hot all day, the 16-ounce Thermos Stainless King Travel Mug was designed with you in mind.


Thermos Stainless King Travel Mug

Thermos Stainless King Travel Mug

 The Spruce Eats / Rebekah Joan

We purchased the Thermos Stainless King Travel Mug so our reviewer could put it to the test in her kitchen. Keep reading for our full product review.

Thermos is a household name for many people—really, who hasn’t used one of their food containers to bring hot soup to work at one point or another? Because of the brand’s reputation for quality, we wanted to see if the Thermos Stainless King 16-Ounce Travel Mug has the same impressive heat retention abilities as other Thermos products. We put it to the test, using it as our daily to-go cup for several weeks—read on to see what we found. 

Design: Clunky in cupholders, but easy to carry

The Thermos Stainless King has a double-walled, vacuum-insulated design that the brand claims will keep drinks hot for seven hours or cold for 18 hours, all while the outside of the mug stays comfortable to the touch. In general, it felt very durable, and we thought the mug was comfortable to hold either by its handle or with our hand around the cup itself.

As far as the lid goes, it has openings on either side, making it comfortable to use whether you’re left- or right-handed. All you have to do to open it is turn a little lever.

Thermos Stainless King Travel Mug
The Spruce Eats / Rebekah Joan

While we had this mug in the car, one thing we realized is that it doesn’t fit well in all cup holders. The body fits snugly, but the handle gets in the way of it settling down. However, if your cup holders are connected, you can turn it so the handle is partially in the next cup holder—assuming the neighboring spot is empty. Either way, it makes it harder to get the mug out for a sip and increases the risk of spilling.

Thankfully, the handle is the only major design flaw we found with the mug, and if not fitting into a cup holder is a dealbreaker, you’ll be happy to know the brand also offers the Thermos Stainless King without a handle.

Performance: Works well in extreme conditions

To test the mug’s heat retention, we made hot chocolate at 9 a.m. and took it to work with us. When we opened the Thermos Stainless King at 2 p.m., the drink’s temperature was still on the hot side of drinkable. We were impressed, but we also wanted to see how well the Thermos Travel Mug would retain heat in more extreme conditions, such as for people who work outside.

The lid has openings on either side, making it comfortable to use whether you’re left- or right-handed.

To test this, we put boiling water into the cup and placed it in our car on a cold, 20-degree day. After seven hours, the liquid was still above 130 degrees, which is within the ideal temperature range for drinking coffee. We’re happy to say that this travel mug stands up to its claims and will keep your coffee hot for most—if not all—of your shift, even on a cold day.

As far as keeping liquids cold, we tested found that the Thermos Stainless King kept ice water refreshingly cold for almost 24 hours. The ice didn’t last that long, though.

Material: Durable stainless steel

This travel mug is made of vacuum-insulated stainless steel, and the lid is made of plastic. Its construction feels very durable, like it would survive a drop or two.

However, it’s worth noting that a few reviewers say the finish on the outside of the mug flaked after six months to a year of use. This wasn’t the case for everyone, though.

Features: Clever lid design

When we first looked at the lid on this Thermos travel mug, we were confused. It looks more complicated than most lids, but after inspecting it further, we realized the design is actually quite clever. Instead of a standard slider to open and close the drinking hole, this lid uses the brand’s “DrinkLock” technology.

Thermos Stainless King Travel Mug
 The Spruce Eats / Rebekah Joan

What does that mean? Basically, there’s a gasket around the rim of the lid that seals it, and below that is an additional disc that moves up and down as you open and close the lid. It forms a tight seal so that no liquid (or heat) passes through it, which means no spills and your morning coffee stays hot for longer.

On top of that, the bottom of the lid also features a hook for tea bags or infusers. That way, you can brew your tea on the go and won’t have to fish around to get the bag out.

Cleaning: Quite the hassle

While the mug itself is easy to wash, the lid has to be taken apart for cleaning. All you have to do is disassemble a few parts and hand wash them, but when you have to do it every day, it gets tedious quickly.

While the travel mug is technically dishwasher safe (top-rack only), the manufacturer recommends against putting it in the dishwasher to preserve the exterior finish. Thermos also suggests not leaving liquids inside the mug for more than 24 hours.

The bottom of the lid also features a convenient hook for tea bags or infusers.

Price: Worth it

The Thermos Stainless King Travel Mug costs $24.99, but it’s often on sale for less. Given the quality performance and construction of the mug, we think it’s a fair price, even if it is higher than other similar-sized options

Competition: These cheaper travel mugs work almost as well

Bubba Envy Insulated Stainless Steel Tumbler with Straw: If you’re looking for a travel mug that’s great for hot drinks and thicker beverages like smoothies, the Bubba Envy Insulated Stainless Steel Tumbler is a worthwhile choice. You can often find it retailing for under $10, and it comes with a winged straw that’s great for stirring your drink. The downside is the Bubba Envy doesn’t have a closable lid, but it does a decent job maintaining drink temperatures and its 24-ounce capacity is significantly bigger than the Thermos Mug.

Ello Campy Stainless Steel Travel Mug: Want a travel mug with an outdoorsy aesthetic? The Ello Campy Travel Mug is it—this cup keeps drinks warm almost as well as the Thermos, and it’s a little bit bigger, with an 18-ounce capacity. The lid on this mug isn’t nearly as complicated, and the whole thing much easier to clean. Plus, its cork-lined handle is extra comfortable! For just under $20, this vintage-inspired to-go cup is a fashion-forward option.

Final Verdict

A keeper.

The Thermos Stainless King Travel Mug might be a little pricey, but it keeps hot drinks hot and cold drinks cold for longer, making it a worthwhile purchase, especially if you work outdoors or have a long commute.


  • Product Name Stainless King Travel Mug
  • Product Brand Thermos
  • Price $24.99
  • Product Dimensions 4.9 x 7.8 x 3.3 in.
  • Product Number SK1000MBTRI4
  • Color Options Cranberry; Electric Blue; Matte Army Green; Matte Black; Midnight Blue; Pine Green; Stainless Steel
  • Materials Stainless steel and plastic
  • Warranty Limited lifetime