Have a Galaxy S8+ and when walking and using the Health App, the calorie count seems way too high and inconsistent. For instance, on the 29th, I did a 35 minute walk for 2.44 miles and the app registered 368 calories. On July 3rd, I did a 39 minute walk @ 1.95 miles and burned 453 calories. July 4th, I completed a 38 minute walk @ 2.13 miles and burned 603 calories.
When I entered the July 4th walk into a couple of other tracking apps, they showed only around ~170 calories burned and were consistent with each other.
I have seen other complaints such as this and people keep citing that Samsung takes into account BMR when at rest, etc.., but that should have little to no bearing on a short duration exercise..