The Best Oven Thermometer Will De-Fraud Your Oven

Preheat the oven. It’s the first step in, well, any recipe that uses the oven. Allowing your oven time to fire up and create the perfect conditions for cooking your dinner or dessert. When it comes to taking the temperature of your actual food, we have plenty of recommendations for the best instant read probe thermometers out there. But what about the temperature of your actual oven?

• Best oven thermometer overall: Thermoworks Square DOT Digital Oven Thermometer, $69 $48 at Thermoworks → Read more
• Best analog oven thermometer: KitchenAid Oven Thermometer, $15 at Amazon → Read more

If you’re an avid baker, your breads and other pastries demand consistent temps. If you’re the designated turkey chef on Thanksgiving, getting the proper doneness could depend on knowing if you have an accurate oven or not.

High heat roasting, low and slow cooks—there are many more projects that will come out better with a good oven thermometer. We tested both probe and dial oven thermometers and models from brands both reputable and mysterious. Read on for more details about our top picks and a definitive answer to whether you should by an oven thermometer at all.

By the way, these are ambient temperature thermometers, not meat thermometers. If you're looking for meat thermometer click over here.

The short answer is: You probably do, at least for periodic use. But the real question is, “how much do I trust my oven?”

If your food tends to come out perfectly at the time and temperature recommended in the recipe, then you can, for the moment, rely on the oven's existing settings to give you a good guess as to the temperature inside.

The tricky thing with ovens though, is that they cycle on and off to conserve energy (you’ve probably heard it happening with electric clicks or the woosh of the flames relighting). That means when you set your oven to 350 degrees Fahrenheit, the temperature is actually fluctuating up and down during the cooking time, cooling a few degrees before the internal thermostat notices and triggers the gas or electric heating element to kick back in. Then it heats things up to more than 350 degrees to make up the difference before shutting off once more. So, what you're really setting when you turn the knob or punch those buttons, is what the oven will target as an average temperature while the door is shut.

If you’re unlucky and your food often comes out underdone, a bit too crispy, or worse, burnt, no matter how diligently you follow a recipe’s instructions, then you might have an oven temperature calibration problem. In other words, your oven isn’t being honest with you about what’s going on inside. This will happen in every home kitchen at some point, perhaps because the oven is cheap (a regular feature in many apartments) or just because the oven is old. That’s when an oven thermometer becomes an essential kitchen tool for making sure your most finicky baked goods or your holiday dinner’s main course comes out correctly and on time.

If you know Thermoworks it’s likely for their Thermapens. They are, in our opinion, the best instant-read thermometers you can get. But the Utah-based company makes more than just food thermometers. They make the best ambient cooking thermometers as well. The Square DOT is a digital thermometer with a readout that sits on the countertop, so you don’t need to try to read it through the glass of your oven door. It has the added benefit of two temperature channels, one to give an ambient temperature reading and one to give an internal temperature reading of what you’re actually cooking at the same time. This is particularly nice if you're using the Square DOT to pull double duty for BBQ in your smoker. It also has an “average temperature mode,” which is, by far, the most precise way to determine your oven temperature. It offers average readings in 15 minute increments that will take into account the cycling of the oven. In a sense, it’s fact-checking what your oven is saying. It can also pull double duty easily in a grill or smoker, where control over temperatures is a bit more, er, manual.

The pressure-mounting metal clip that holds the probe was too narrow to clip on to our oven rack grates. It might not be for yours, but the fact that it didn’t fit our testing oven means it’s not universal. After bending it open a bit the clip did fit more snugly, but pulling on the probe wire could twist it out of position causing it to fall. And unlike the analog thermometers we tested, it requires batteries and a wire running out of your oven door. Wire no though, if you do need to check the ambient temperature while you’re cooking, this will give you an accurate reading no matter where you put it.

Of all the analog thermometers we tested, KitcheinAid’s stayed in an acceptable ±5-degree range most often. Its three-inch dial was easy to read well with its bold, red indicator needle and we liked that the dashes on the dial were marked down to five-degree increments. It was also the sturdiest in both the hanging and standing positions, as it actually uses a metal clip to cling to the oven rack, no dangling or toppling problems at all.

Installing the clip-on hook is a bit finicky at first (this isn’t the case in a KitchenAid brand oven because there’s a horizontal gap toward the front of the rack where the thermometer is designed to go.) That said, it did clip securely onto the crossbars of our oven rack, and, though the gaps in our oven grates were too wide, it features slots that can accommodate hanging it between those front-to-back wires if your spacing is more compact than ours. While the numbers on the temperature gauge were smaller and less bold than we might have liked, given its accurate performance when placed at the front of our oven — where it was extremely easy to read —we thought it was the best of its bunch.

The only instance where KitchenAid’s thermometer fell short was in the high temperature test. It ran too hot by about 20 degrees Fahrenheit. However, given that kinds of cooking that happen at 500ºF are often shorter and demand you watch your food anyway, we think it’s a little less important that an oven thermometer hit exactly the temperature there than at 350ºF, where 20 degrees in either direction could really mess up your cookies.

Every oven is different, and even though lots of them look the same, many oven thermometers are a bit different, too. This presents some challenges when pitting thermometers head-to-head. We used the ThermoWorks Square DOT’s average temperature feature to create our baseline. First, we dipped the ThermoWorks probe (both with its averaging feature turned on and without it on) into a pot of boiling water for 15 minutes to determine its calibration with a known temperature of 212º F. The probes read 211º F, which is pretty darn accurate (and a smaller discrepancy than the ±1.8º the manual promises). We adjusted the results of all of our ThermoWorks probe findings by one degree to get the “real” temperature (we could have done this as a percentage change, but it only would have changed our calculations by about .5 degrees).

Next, we hung all of the analog thermometers in the same oven within inches of the center. Because the food can get in the way, oven thermometers won’t always be able to hang out in the middle of the middle rack, but we felt this was the fairest way to determine overall ambient temperature accuracy with regard to where the food you’re cooking would actually be sitting. Part A of this portion involved preheating the oven to 350º F and taking a reading of each thermometer. Then we set a timer for 25 minutes (somewhere in between a long preheat and a short bake) and checked the readings again after the oven had a chance to cycle off and on a couple of times. Next, we repeated this same procedure at the higher-end cooking temperature, 500º F. We made our calls on the accuracy of each thermometer based on how close each was to the adjusted ThermoWorks average temperature at both the short and long preheat benchmarks at both temperatures. We then repeated this process once more with all of the thermometers placed in the front of the oven, right by the door, to see if their location had any effect on overall consistency.

Finally, we tucked all of the thermometers in the back corner of the oven to test their readability at a quick glance. We also hung and stood up each thermometer and jostled the oven rack in and out to determine a thermometer’s stability in both positions.

Here's how we judged the thermometers:

Judging the accuracy of a thermometer without a detached probe is tricky, but using the Thermoworks probe in boiling water as our baseline we got a pretty good idea.

We wanted a thermometer that didn't take more than a quick glance through the oven glass to read.

We wanted a thermometer that would stand or hang easily in as many parts of the oven as possible. That way we'd feel confident using it whether we had a huge roasting pan in the oven or just a small sheet pan with a few cookies.

We should note that once you get to know your oven a little better, you don't necessarily need to leave your thermometer inside the oven forever. Just use a thermometer to figure out if your oven runs hot or cold, and adjust your oven’s temperature settings up or down accordingly. Then recheck it a few times a year to make sure it’s still where it should be. Also, keeping your oven thermometer in your oven permanently may affect its performance over time.