Jane McGuire of Tom’s Guide reported close results for the Apple Watch Ultra 4 and Samsung Galaxy Watch Ultra 2 in one half marathon: 13.23 miles versus 13.21 miles, with average heart rates of 159 and 160 beats per minute. Tom’s Guide named no clear performance winner, and one race cannot settle which watch is more accurate overall. McGuire’s account describes her reported results.
What the watches recorded
McGuire enabled auto-lap on both watches and said their lap markers largely lined up with the course markers. Here are the measurements she reported for that run:
| Watch | Distance recorded in one half marathon | Average heart rate in that run |
| Apple Watch Ultra 4 | 13.23 miles | 159 bpm |
| Samsung Galaxy Watch Ultra 2 | 13.21 miles | 160 bpm |
The distance readings differed by 0.02 miles. That small gap, alongside a one-beat-per-minute difference in average heart rate, gives no basis for a broad accuracy ranking.
McGuire did not wear a chest strap. She used an Oura Ring 5 as a comparison for heart rate; it read 163 bpm. That reading offers context for the outing, not a chest-strap reference.
One race, limited conclusions
The reported figures belong to one runner’s half marathon. McGuire also reported 311 feet of elevation gain for the course and 342 feet recorded by the watch. She raised altimeter sensitivity, GPS drift and weaving through other runners as possible contributors to the difference, rather than identifying a proven cause.
McGuire found both watches bulky on her petite wrist and said the Samsung felt slightly wider. She reported that both displays remained legible in direct sunlight; the Samsung’s physical buttons also helped when her fingers were sweaty. Those are her observations from one run, not a fit verdict for every wrist.
Phone compatibility may decide the choice
Apple requires an iPhone 11 or later—including iPhone SE (2nd generation or later)—running iOS 27 or later for Apple Watch Ultra 4. Apple’s technical specifications give the full requirement.
Samsung says Galaxy Watch Ultra2 works with Android phones. But a compatible Galaxy phone is required for ECG, Irregular Heart Rhythm Notification, Sleep Apnea and Running Coach, according to Samsung’s August 31, 2026 statement. So an Android phone can meet the watch’s general compatibility requirement while leaving those named features tied to a Galaxy phone.
If you’re weighing Apple Watch Ultra 4 for other reasons, NeoTeo has also covered it in a separate article about Apple Watch and wiretapping-law questions.
