Best Baby Thermometers (2026): Which Type by Age

Which thermometer to buy depends on the child's age, whether it's the first one bought before the baby arrives or a second as a child grows. Eight digital and infrared thermometers are compared against the American Academy of Pediatrics' guidance on which method to use at which age.

The fever guidance below is quoted from the AAP's HealthyChildren guide to taking a child's temperature (last updated April 2024). This is a buying guide, not medical advice; if your child is unwell, call your pediatrician.

How we chose: we compared eight digital and infrared thermometers, each sold by Amazon.com or the brand, on type, speed and memory as their listings state them; speed and accuracy figures are the brands' claims, and we did not test them.

Which method the AAP recommends at each age

The AAP also says: "Do NOT use a mercury thermometer." Every thermometer here is digital or infrared.

The eight thermometers side by side

Prices are Amazon's, as of the time shown, and subject to change. Details

What counts as a fever, and when to call

The AAP defines it this way: "A fever usually is a temperature of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher."

It also says when to call: "Call your pediatrician right away if your child: is 2 months old or younger with a rectal temperature of 100.4 degrees Fahrenheit or higher, or if fever rises above 104°F (40°C) repeatedly at any age."

Key point: this is why the method matters for a young baby. A single rectal reading of 100.4°F or higher at 2 months or younger is a reason to call right away, so that reading should come from the most accurate method.

Several thermometers here have color-coded screens, green for normal and yellow or red for higher readings, but each brand sets its own thresholds. Give your pediatrician the number, not the color.

Rectal thermometers for the first months

The AAP describes a rectal reading as "the best reading, especially for infants under 3 months of age." Four picks here can take one:

• Safety 1st 5 Second Read is the fastest stick here, per its listing, and the listing cites the AAP's advice on rectal temperatures for young children.
• Frida Baby Digital Rectal is made only for rectal use, with a flexible tip, a 10-reading memory and a case.
• Vicks SpeedRead works orally, rectally or under the arm, with a color-coded display.
• Kinsa QuickCare adds an app that logs readings and symptoms for each family member. It is sold by Kinsa Health rather than Amazon.com.

If you buy a multi-use stick such as the Vicks or Kinsa, label it for rectal use only, and buy a second one for oral or underarm use as your child grows.

Forehead and ear thermometers

These read in one or two seconds, per their listings.

• Braun No Touch 3-in-1: reads the forehead without touching it. Braun states ±0.4°F accuracy and a silent mode for a sleeping child.
• Frida Baby 3-in-1 Infrared: combines ear, forehead and touchless modes, with a 40-reading memory.
• iProven Ear and Forehead: switches between forehead mode (cap on) and ear mode (cap off). It is sold by iProven.
• Braun ThermoScan 7+ Connect: an ear thermometer with a pre-warmed tip, a positioning light and beep, and a phone app.

For a new baby, a forehead thermometer is the second one to buy, because the AAP says it works at every age. An ear thermometer becomes an option at 6 months.

Braun says the ThermoScan 7+ Connect is "as accurate as rectal measurements in newborns". That is the brand's claim. The AAP's guidance is that ear thermometers are "Not reliable for younger babies" and are for children 6 months and older, so follow the AAP for a baby under 6 months.

Smaller differences

• Memory. When you call the pediatrician, a list of readings and times helps. The Frida 3-in-1 stores 40 and the iProven 20. The Frida rectal and Braun No Touch store 10.
• A silent mode. The Braun No Touch can switch off its beep, so you can check a sleeping child without waking them.
• Easy cleaning. The Frida rectal and Vicks SpeedRead are listed as water-resistant.
• The seller. Every thermometer here is sold by Amazon.com, except the iProven (sold by iProven) and the Kinsa (sold by Kinsa Health). We left out a well-known temporal-artery brand because we found it only from resellers.

Related: the baby registry checklist on a budget for the rest of the first-aid list, the babyproofing checklist by age and our baby product recalls page, worth checking before buying any health product secondhand.

Frequently Asked Questions

How do I take a baby's rectal temperature?

Gently, and not deep. The AAP's guide says to put "a small amount of lubricant, such as petroleum jelly, on the end of the thermometer and on your child's bottom," then "slide it 1/2 inch (for babies less than 6 months old) to 1 inch into the anus."

Is an underarm temperature accurate?

Not very. The AAP says "armpit temperatures are the least accurate, but you can use this method to screen a child of any age." Confirm a high armpit reading with the method the AAP recommends for your child's age.

How do I clean a baby thermometer?

Before and after every use. The AAP says thermometers "should be disinfected before and after use with disinfecting soap and water or disinfecting alcohol swab."

This guide is for general information and is not medical advice. If you are worried about your child's temperature or health, contact your pediatrician.