The Best Baby Thermometers for Getting an Accurate Temperature

Why is a rectal thermometer at the top of our list? Because, according to doctors, using a rectal thermometer is the most accurate way to take baby’s temperature—and that accuracy is important when your baby is sick.

This rectal thermometer from FridaBaby—a brand beloved by parents for all their baby and postpartum health products—may be small, but it does a big job. Pediatricians will tell you that there's no replacement for a rectal temperature’s accuracy, but it’s a notoriously tough task: you’re taking an already fussy, potentially feverish baby and making them even more uncomfortable. That’s why a fast-acting thermometer is essential, and FridaBaby’s rectal thermometer gives a temperature readout in just 10 seconds. 

The main reason this is my go-to rectal thermometer, though, is the digital screen. It’s nearly twice as big and twice as bright as other rectal thermometers, and the backlight makes it really easy to read in the dark. It also stores the most recent temperature reading (though you can’t go back any further than that).

It’s also shaped with a short tip and a flared base to stop you from over-inserting it—a common concern among parents. “The shape makes me more confident that I won't hurt [my baby] accidentally by stopping the thermometer at the right position,” Kat M. says. The tip is also really flexible to provide maximum comfort for your baby. Just remember to always use a lubricant like petroleum jelly before inserting, and clean the tip extra well with an alcohol swab as soon as you’re done.

But while this may be my favorite rectal thermometer and a favorite among lots of parents, my biggest gripe about the FridaBaby thermometer is that it’s kinda small. I’d say my hands are about average size, and I sometimes feel like I’m going to lose my grip on it. It’s honestly something I didn’t think was fixable until I tried the thermometer below, which has convenient finger indents on the side to help you hold it tighter. 

I’d also love if this thermometer had an alert or indicator of whether the temperature is in the fever range. Plenty of thermometers out there have a color-coding system or something similar, and that kind of feature would truly make this the perfect thermometer for babies.

Similar to the one from FridaBaby, this rectal thermometer from Vicks is quick and comfortable, ensuring you get a reliable temperature without having to prolong the experience for your baby. You get a clear digital readout on the screen after just 10 seconds or less, and you can recall the most recent temperature with the touch of a button. The screen is smaller than the FridaBaby, but the backlight is bright enough to still be read easily even in low light.

Even more importantly, it’s shaped so that the tip can only be inserted a certain amount so as to not injure your baby. Most rectal thermometers out there don’t have that kind of wide taper, so you have to use your own judgment on how far you’re inserting it. That’s why I always recommend choosing a rectal thermometer like this or the FridaBaby.

And you can be sure you won’t lose your grip on this thermometer, either—there are indents on either side so your thumb and finger can keep a stable grasp. The only downside to the placement of the finger grips is that it’s also where the on/off button is located, so just be sure to not hold it too tight or you might reset the reading.

The main thing to keep in mind about this thermometer, based on my experience and the experience of other parents, is that the first reading may not be accurate. “During my son's recent cold, I would take his temperature with this in sets of 3,” Kiki says in a product review. “The first reading was almost always 0.2 degrees lower than the 2nd and 3rd (which were consistently the same).” I don’t know if it’s because the metal tip needs a chance to warm up or if it’s some issue with the internal computer, but the first reading always seems to be a little low, and then the second/third/fourth readings will all be the same as each other. So just keep in mind that every time you go to take baby’s temperature, you might want to take it two or three times just to be sure. While not a total dealbreaker, it can be a little annoying (for both you and baby).

Also slightly annoying is the storage cap. I was actually excited at first that this thermometer included one so I could make sure that it stayed clean and the tip wouldn’t accidentally get bent, but after a couple of months the cap just wouldn’t stay on anymore. No matter how I tried to secure it, it slipped off with the slightest bit of jostling.

And finally: be careful how you wash this thermometer. Multiple reviews have noted that if you try to wash the entire thing, moisture can get trapped in the screen and make it hard to read or in the battery compartment and compromise the entire unit. To keep your thermometer working properly, you only need to clean the tip with an alcohol swab or a wet, soapy cloth.

Vicks has long been a trusted brand for all things health-related, so it’s no surprise that two of their thermometers made this list. I love their SpeedRead thermometer for several reasons, mainly the extra features that most rectal thermometers don’t have.

The large, easy-read screen features a color-coded fever indicator, which turns green for no fever, yellow for an elevated temperature and red for a higher fever, “so you know before you even look at the number if you are running high or low,” one parent says in their review. It also has a rotating display so you can read it no matter which direction you’re facing.

And while most thermometers have around a 10-second read time, the Vicks SpeedRead boasts an eight-second read—those extra two seconds may not seem like much, but any amount of time can feel like an eternity when you’re awaiting results with a sick baby.

Speaking of which, you’ll be able to use this thermometer for more than just your baby. While rectal temperatures are the most accurate for ages 12 months and under, it’ll be a lot harder to do it that way when your baby becomes a toddler or a preschooler. Thankfully, this 3-in-1 thermometer also takes temperatures via the armpit and mouth, so you can use it for years to come and the whole family can use it. 

If you’re weirded out by the thought of using a rectal thermometer as an oral thermometer, that’s totally understandable. You can purchase separate disposable covers to help keep everything sanitary (it unfortunately doesn’t come with any), and many reviews have said that the thermometer itself is “easy to clean” with soap and water or an alcohol swab.

The biggest thing to keep in mind is the shape of this thermometer—unlike the other rectal thermometers on this list, there’s no wide base to act as a stopper. If you’re using it as a rectal thermometer for your baby, you’ll need to be aware of how far you’re inserting it to make sure you don’t hurt them. The tip should go in no more than half an inch. If you feel any resistance, don’t push.

While rectal thermometers are by far the most accurate option for getting your baby’s temperature, sometimes your little one might just be too fussy. If that’s the case, a no-contact thermometer can come in handy (especially when baby is sleeping). Just a quick scan two inches away from their forehead and you’re good to go. There’s also no risk of cross-contamination if other people are using the thermometer.

I love every thermometer that Kinsa makes, and this no-contact version is no exception. Kinsa thermometers can be used on their own, but their biggest perk is the free health tracker app. With the Kinsa app, you can see all previous temperature readings and the times they were taken, get advice based on how high the temperature is (it’ll tell you when you need to see a doctor) and even set up profiles for every family member and assign separate temperature readings to them, a feature one parent called “genuinely helpful.” You can also log other symptoms and get customized treatment options—it’s truly like having a nurse hotline directly connected to your thermometer. One user mentioned they could even sync the thermometer and the app to their Apple Watch.

It’s more expensive than a basic thermometer, but if you’re the type of parent that prefers to keep track of your baby’s temperature changes and symptoms in a convenient app, then the Kinsa QuickScan is worth the extra cost.

This is the only thermometer on this list that provides temperature alerts based on your child’s age right there on the thermometer itself (not in an app), which is extremely helpful if you’ve got multiple children in different age groups. In the settings, you can input whether your child is 0-3 months, 3-36 months or 36+ months, and the thermometer will automatically adjust the color-coded system to show whether your little one has a dangerous temperature for their age.

And while most thermometers only store the most recent temperature reading, this one stores the past nine. But it can’t separate previous readings for different people like the Kinsa can.

The most unique feature about the Braun Ear Thermometer, though: the pre-warmed tip. The metal tips of other thermometers (the rectal, ear, armpit and oral kind) are notorious for being cold and can sometimes lead to inaccurate first readings, like with the Vicks rectal thermometer on this list. But not this one! The tip self-warms when you turn the thermometer on so that you can get an even more accurate reading.

The American Academy of Pediatrics (AAP) says it’s fine to use an ear thermometer on babies older than six months, since at that point their ear canals are likely large enough for it to not be uncomfortable, but if your little one is suffering from a painful ear infection, trying to get anywhere near their ears could be a problem, so you may want to try a different type of thermometer.

If you’re looking to keep constant track of your baby’s temperature, it can be annoying to use a thermometer over and over again (especially if you’re using a rectal thermometer). That’s where these innovative thermometer stickers come in handy. 

They stick right to your baby’s forehead and get you an accurate temperature in 15 seconds or less. From there, they provide a continuous temperature readout for up to 48 hours, so all you have to do is glance down at your baby to keep track of where their fever is at. They’ll continue to stay on even if your little one is moving around a lot, but some people have noticed that they don’t stick very well if baby’s forehead is sweaty, so be sure to wipe off their skin first.

The display clearly shows a green dot over the degree number—it only measures temperatures in ranges rather than exact degrees, but there’s a specific dot to indicate 100.4°F (the threshold for a fever when taking a forehead temperature).

I love using these on my toddler when he’s sleeping so that I don’t disturb him with an ear or armpit thermometer every hour, but they definitely don’t work for us when he’s awake, since he always yanks the sticker off right away. A younger baby likely wouldn’t be able to, but remember that rectal thermometers are the best option for younger babies anyway.