The Best Just Got Better | Thermapen ONE Review

I have long been a Thermapen fanboy. ThermoWorks makes fantastic products and the Thermapen series of instant-read thermometers are no exception. I purchased (or was gifted by my dad – I don’t remember which to be honest) a black Thermapen Mk4, about five years ago. Since I first got it the Thermapen Mk4 has been my go-to instant-read meat thermometer. It’s durable, reliable, and intuitive. It just works. The Thermapen Mk4 has since been replaced by the Thermapen Classic and the Thermapen ONE. The Termapen ONE was released a year or two ago as an upgraded Thermapen with 1-second temperature readings. We got our hands on the Thermapen ONE to test.  Does it live up to the hype? Is it worth the money?

Note: This post contains affiliate links. If you use these links to buy something we may earn a commission, at no cost to you. Thanks for supporting The Grilling Dad. Full details here.



  • Easy-to-read backlit LCD display
  • Waterproof (IP67)
  • Display rotates in 90° increments
  • Durable
  • Ergonomic design makes it easy and comfortable to grip
  • Available in 11 colors


  • No “hold” button for those tough to read probe angles
  • Only 180° of probe rotation which is limiting for left-handed users
  • No magnets or hanging loops like the Typhur InstaProbe and ChefsTemp Finaltouch X10

Use Cases

  • Ideal for gilling (never overcook a meal again):
    • Burgers
    • Chicken
    • Fish
  • Fantastic for BBQ and long cooks
    • Brisket
    • Pork butt
    • Thanksgiving turkey
    • Christmas ham

Quick Verdict

If the Thermapen ONE had a hold button and 270° probe rotation it would be nearly perfect and would leave all other competitors in the dust. Without those features it is still our favorite instant-read meat thermometer (though we do also really love the Typhur InstaProbe). The Thermapen ONE just works. Its durable build and IP67 rating help it to stand up to some abuse. It’s fast and accurate. Its form factor and the band of rubber that runs along its edge make it comfortable to hold and secure in your hand. The Thermapen ONE is on the pricey side at a typical price of $109, but it does periodically go on sale. Right now you can get it for under $75. The Thermapen ONE is the current gold standard in instant-read thermometers. It does not disappoint!



The ThermoWorks Thermapen ONE has a very wide sensing range of -58 to 572°F. This means it can be used for a wide array of cooking tasks including BBQ, grilling, and caramel or candy making. It can achieve 99.3% accuracy within 1 second over the temperature range of -4 to 248°F. That sentence might make your head spin a bit so let’s apply it to an example. Let’s say you are cooking an amazing wagyu ribeye and you want it a perfect medium rare so you want to pull it off the grill between 125 and 130°F. You sear it for a couple of minutes on each side and then you probe it. The probe reads 127°F after 1 second. You can be confident that the actual temperature of the ribeye is no more than 127.9°F and no less than 126.1°F. Within 0.9°F in 1 second. That is pretty amazing. Over the temperature range of -4 to 248°F the Thermapen ONE allows absolute precision when grilling, barbecuing, and smoking. Perfectly grilled burgers, chicken breasts, and fish. Every. Single. Time. The quick response time also ensures that your hand doesn’t have to spend an extended period of time over a several hundred degree grilling surface! I’m all for that!

In our water boil and ice bath temperature tests the Thermapen was very accurate and fast. While it is difficult to actually time the response, the Thermapen ONE never felt slow and that is always my gauge. The Thermapen ONE settled out right around 32.5°F. I deem this a pass because the mixture of ice and water is unlikely to ever achieve a steady-state 32°F in a kitchen test. In our boil test the Thermapen ONE settled out just over 210°F and based on my altitude, water should boil at 210.4°F. From an accuracy standpoint I would say the Thermapen ONE aces the test.


I love that the Thermapen ONE requires a single AAA battery. It even comes pre-installed. I have griped about other instant-read thermometers that require CR2032 batteries or other obscure batteries. Now coin batteries aren’t super rare or hard to find, but as a dad (hence “The Grilling Dad”) I have a ton of AAA batteries at my house so I really appreciate that ThermoWorks powers the Thermapen ONE with a super common household battery.


Now let’s talk about the screen for a little bit. My Thermapen Mk4 has an orange backlit. I’ve never had any issues reading that in the pitch black middle of the night, but the Thermapen ONE uses a light blue backlight that creates much higher contrast with the black LCD digits on the display. The result is a much more readable display.

Thermapen ONE screen next to Thermapen MK 4 screen

Like the Mk4 the Thermapen ONE screen also rotates a full 360° in 90° increments. This makes the display easy to read no matter how the probe is oriented. This is really a standout feature and the only thing that would enhance this feature is if the probe rotated at least 270°. That would make the Thermapen ONE more useful for left-handed cooks.

Thermapen ONE showing all four rotations of the screen


I really like the ergonomics of the Thermapen ONE. It is very comfortable to hold in your hand. It has slightly sharper edges than the Mk4. That doesn’t diminish how comfortable it is to handle and I think it makes the Thermapen ONE look more modern, which I like. There is a rubberized gasket that runs around the edge of Thermapen ONE that helps to seal the probe from dust and water, but it also makes it very grippy. You never feel like the Thermapen ONE is about to slip out of your hand. When you’re grilling or smoking meats your hands can get slick with fat or grease so you really want an instant-read that feels secure in your hand. The Thermapen ONE really nails that. Like the M4 the Thermapen ONE also has a little bump on the bottom that your pinky rests on when using the probe. When not in use the probe folds into this bump which protects the probe tip from damage and protects you from the sharp probe tip. ThermoWorks isn’t the only manufacturer to make use of a feature like this, but they pull it off better than the ChefsTemp Finaltouch X10 and the Maverick PT-51.

Thermapen ONE rubber gaskets

Overall I really love the Thermapen ONE. It takes everything that was great about the Thermapen Mk4 and just makes it better. The Thermapen ONE is second to none.


The Thermapen ONE is tied with the Typhur InstaProbe as the most expensive instant-read thermometer we’ve tested. The Thermapen ONE is typically $109, but specific colors go on sale from time to time for as little as $71. I think the Thermapen ONE is a great value at $109 and well worth it for committed backyard cooks. When it is on-sale it is an absolute no-brainer. If you’re more price sensitive, watch for sales around any major US holiday.


The Thermapen ONE is primarily constructed of textured plastic and a rubber-like polymer. It feels extremely durable and while I would NOT recommend dropping it on purpose, I do think it would easily survive a fall from counter or grill height. The Thermapen ONE is IP67 rated which means if you forget it out in the rain or accidentally drop it in a sink full of soapy water it will be just fine. 

Who Is It For?

The Thermapen ONE is for those grill masters and pitmasters that are really committed to their craft. If you aren’t sure whether outdoor cooking is for you I’d recommend getting a less expensive (though also poorer quality) instant-read thermometer. But if you know you love grilling or BBQ and you are ready to start investing in tools that will help you get better and are built to last, the Thermapen ONE is the instant-read thermometer for you. Like to cook fish? The Thermapen ONE can help you get that perfect moist, flaky fish you dream of. Grill chicken and burgers? When the juices from your chicken breast (not thighs) are running down your chin you’ll remember this review. BBQ pork butt and brisket? When you test that slice of the lean brisket and it’s juicy and tender because you pulled it at just the right temperature, you’ll thank me. Trust me – you want the Thermapen ONE.

Do You Really Need An Instant Read Thermometer?

The short answer is no.  With enough patience and practice, all you need to cook delicious food for your family and friends are the ingredients and a fire.  That being said, assuming you already have a grill, an instant-read thermometer is THE MOST CRITICAL piece of grilling kit you can buy.  It offers peace of mind, it levels the playing field for beginners, and for cooks like burgers, chicken breast, and fish an instant-read thermometer will have a massive impact on the quality of the food you cook. I would go so far as to say that an instant-read thermometer will help you consistently cook burgers, chicken, and fish better than any of your friends and family that don’t use an instant-read thermometer.  It would be very difficult for me to overemphasize the importance and impact that an instant-read thermometer can have on the quality of the food that you cook, particularly as a beginner.

Final Thoughts

If you are committed to grilling or barbeque do yourself a favor and invest in a Thermapen ONE. It is fast and accurate, will improve the quality of food you make, and last a very long time. You’ll thank me later.


Sensing Range-58 to 572 °F (-49.9 to 299.9 °C)
AccuracyWithin 0.5 °F (0.3 °C) for temperatures between -4 and 248°F otherwise +/- 1.8°F
Screen Resolution0.1 °F (comes set at 1° from factory)
Response Time1 second @ 99.3% accuracy
Display TypeBacklit LCD
Sleep ModeUser selectable from 10 to 180 seconds: Can also be turned off altogether
Water ResistanceIP67*
Battery(1) 1.5V AAA Battery (included and installed)
Battery Life2,000 hours without backlight
CalibrationIncludes NIST-traceable calibration certificate
Warranty5 years

*IP67 indicates complete protection from dust as well as protection against submersion in water up to 1m deep for short periods of time

Leave a Comment