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Short answer: For the car, get the Thermos Icon 12 oz Tumbler ($21.99 at Thermos). It is cup-holder compatible and rated 14 hours cold. For the desk, get the 14 oz Icon Mug ($24.99). It has a handle, holds 2 oz more and is lighter. Both are rated 3 hours hot and fit most single-serve coffee makers.
How we compare: every spec in this article comes from official manufacturer specifications and product pages (starting with Thermos’s official tumbler page and mug page), all listed under Sources below. We don’t run hands-on tests, and if a spec isn’t published, we say so. Last updated: October 2026.
I live in Japan, where desk mugs with lids are popular in offices. Thermos US sells two Icon pieces in this role, one shaped for the car and one for the desk.
I haven’t tested these side by side. Everything below comes from the manufacturers’ official product pages, linked at the end. If a spec isn’t published, I say so instead of guessing.
Quick Comparison Table
| Spec | Thermos Icon 12 oz Tumbler | Thermos Icon 14 oz Mug |
|---|---|---|
| Capacity | 12 oz (350 mL) | 14 oz (410 mL) |
| Height | 6.2 in | 4.9 in |
| Width x depth | 3.75 x 3.5 in | 5 x 3.9 in (incl. handle) |
| Weight | 0.8 lb | 0.7 lb |
| Hot rating | Up to 3 hours | Up to 3 hours |
| Cold rating | Up to 14 hours | Up to 10 hours |
| Handle | No | Yes |
| Cup holder | Cup holder compatible | Not stated |
| Lid | Slide lock lid with Lumiview window | Slide lock lid with Lumiview window |
| Dishwasher | Dishwasher-safe lid | Dishwasher safe (top rack recommended) |
| Thermos list price | $21.99 | $24.99 |
| Origin | China | China |
All figures are from Thermos’s US product pages, checked October 2026. List prices are Thermos.com prices, not Amazon prices.
Key differences at a glance
- Shape: The tumbler is tall and cup-holder compatible, while the mug is short at 4.9 inches and has a handle.
- Capacity: The mug holds 14 oz, while the tumbler holds 12 oz.
- Cold rating: Thermos rates the tumbler for up to 14 hours cold and the mug for up to 10, and both are rated up to 3 hours hot.
- Price: Thermos lists the tumbler at $21.99 and the mug at $24.99.
- What stays the same: Both have the slide lock lid with a Lumiview window, a Griptec non-slip base, 18/8 stainless steel and a fit under most single-serve coffee makers.
The 4 Differences That Matter
1. Car versus desk
Thermos calls the tumbler cup holder compatible. The mug’s handle and 4.9-inch height make it a desk or home mug.
2. How much coffee
14 oz versus 12 oz. The mug holds a little more despite being shorter.
3. Cleaning
Thermos says the tumbler’s lid is dishwasher safe. It describes the mug as dishwasher safe, with the top rack recommended.
4. Cold drinks
Thermos rates the tumbler up to 14 hours cold, versus 10 for the mug.
What’s the same
Both are double-wall vacuum-insulated 18/8 stainless with a slide lock lid, a Lumiview window to check the drink level, a Griptec non-slip base and a sweat-proof exterior. Both are rated up to 3 hours hot and fit under most single-serve coffee makers.
Who Should Buy Which?
Choose the Icon 12 oz Tumbler if you:
- Drink coffee in the car
- Want the longest cold rating
- Want the lower price
Choose the Icon 14 oz Mug if you:
- Drink at a desk
- Want a handle
- Want the extra 2 oz
The View from Japan
We didn’t find the Icon line on Thermos Japan’s site. Its closest everyday piece is the 真空断熱マグカップ JDG-352C, a 350 mL lidded desk mug that Thermos Japan rates at 67 °C or above after 1 hour, a shorter test than the 3-hour US rating.
A Japanese reviewer on Kenja no Kaimono who used the JDG-352C was surprised that coffee stayed warm for over an hour in winter and that cold drinks didn’t sweat on the desk. They found the lid covered the mouth well enough even though it isn’t fully sealed, and that the simple design was easy to wash. (Third-party reviews of a related Thermos mug, not our own testing.)
Want a longer heat rating for the commute? See Zojirushi SM-VH48 vs SM-KHE48.
Thermos Icon 12 oz Tumbler vs 14 oz Mug: Frequently Asked Questions
Does the Thermos Icon tumbler fit in a cup holder?
Thermos says the 12 oz tumbler is cup holder compatible.
How long does the Icon mug keep coffee hot?
Thermos rates both the 14 oz mug and the 12 oz tumbler up to 3 hours hot.
Will they fit under a Keurig-style coffee maker?
Thermos says both are compatible with most single-serve coffee makers.
Are they dishwasher safe?
Thermos lists the mug as dishwasher safe (top rack recommended) and the tumbler’s lid as dishwasher safe.
Check current listings
Prices and colors change often, so check the current listing before buying.
Related comparisons
- Zojirushi SM-VH48 vs SM-KHE48: GoCafe or Classic 16 oz Mug?
- Zojirushi SM-VH48 vs SM-VH60: 16 oz or 20 oz GoCafe Mug?
- Thermos FUNtainer 16 oz vs Icon 16 oz Food Jar: Which?
- Zojirushi SM-KHE36 vs SM-KHE48: 12 oz or 16 oz Travel Mug?
Sources
- Thermos, 12oz Icon Tumbler with Slide Lock Lid (official): https://thermos.com/products/12oz-icon-tumbler-with-slide-lock-lid
- Thermos, 14oz Icon Mug with Slide Lock Lid (official): https://thermos.com/products/14oz-icon-mug-with-slide-lock-lid
- Thermos Japan: JDG-352C mug specs (thermos.jp): https://www.thermos.jp/product/detail/jdg-352c.html
- Kenja no Kaimono: Thermos JDG-352C review (Japanese): https://kenjano.jp/shopping/15581
Specs checked October 2026. Prices and availability change, so check the current listing before buying.
