Unlike the fragile mercury-filled products of the past, today's digital thermometers give speedier (typically 30 seconds or less) and more accurate readings, and feature more user-friendly designs. Current digital thermometers take readings in one of several ways: oral, rectal, tympanic (ear), forehead and axillary (underarm).
However, according to our research, accuracy among methods can vary. For instance, rectal thermometers, an option for very young children who can't properly use oral thermometers, are the most highly recommended for their accurate temperature readings. Conversely, digital ear thermometers, while also convenient and fast, can be trickier to use.
Overall, reviewers from ConsumerReports.org and experts from health sources like the Mayo Clinic give one common guideline when shopping for a digital thermometer: Go basic. Inexpensive, basic digital thermometers that read oral, rectal and underarm temperatures are considered to be the best value, because they can provide accurate readings for individuals of any age. A basic digital thermometer which can be used orally, rectally or under the arm generally costs between $10 and $25.
High-tech digital thermometers with more bells and whistles have become more popular in recent years, because these flashier products provide additional features like calendars, cleaning alerts and readout alarms, and backlights for better vision. However, these technologies, while convenient, aren't essential, experts say. And these thermometers can be very expensive, typically costing between $20 and $50 or more.
The bottom line: Basic thermometers offer the best value. Experts repeatedly say high-tech products aren't any more accurate than simpler budget thermometers. We did, however, find a few high-tech options that earn high marks from both professionals and owners if you prefer the more advanced and easy-to-use gadgets.
To identify the best digital thermometers in each category, we analyzed hundreds of owner-written reviews across sites such as Amazon.com, Walmart.com, Drugstore.com, Target.com and Viewpoints.com. A number of professional consumer testing organizations have also evaluated digital thermometers, including ConsumerReports.org, Which? magazine, Choice magazine and Consumer magazine; however, not all of the models tested are available in the U.S.