any problem with fenix 6 sapphire calories accuracy overall comment here please

How much is the discrepancy, I ask as working out exact calorie burn is pretty much a black art. I guess the different HR sensor, yielding slightly different results, will result in some differences. Is it a consistent over/under, or does it fluctuate.

And most importantly, I would add it would be hard to tell which one is the more accurate, though I would suspect the newer watch would have better algorithms for calculating.

For example, for a dog walking activity GC says 219 cal, Strava says 319 cal.

I'd pick one and use that as the golden standard (for me, GC as I use My Fitness Pal to monitor input)..

Certain stats (like VO2) are ones I don't worry about the absolute value (as some of them are quite difficult to calculate) and instead I worry about the relative value (i.e has it gone up or down.)

With some of these stats, it's hard to say who is the most accurate. If you wore a Polar, Suunto and both Garmins and did an activity they'd all probably differ in the absolute value of calories, But looking at trends (for the same run, do I use more or less) probably has more worth.

The calorie burn always seems a little low to me. 

https://forums.garmin.com/outdoor-recreation/outdoor-recreation/f/fenix-6-series/195706/calories-burnt-too-low

I'd double check your activity class and profile data

I'm seeing very little discrepancy - here are two similar runs, the first on a 6 pro, the second on a 5x plus (The 6 pro data is from June, the 5x+ is from November IIRC)

(F6 Pro)

(F 5x +)

Be warned when checking comparable activities between two devices, to look also at your average and max HR per session

For the 6 pro activity -

For the 5x+ activity

Usually the calculation that you see in the Internet are HR only based,, some use a factor based on the time spent each week  exercising.

When I bought the fenix 5 noticed that calories count were lower than the above algorithms. However I beleive that they are closer to reality. 

Anyway basal calories are more important  and I doubt if it is easy to calculate them. 

Fenix uses firstbwat algorithm that is vo2max based. More information here.

www.firstbeat.com/.../

I have 3 Fenix watches and there doesn't seem to be much difference in calories calculated by each for the same activity or for base metabolism.

Here is an example of calories from an MTB ride (no power meter) from all three watches, plus a couple of other devices. The Fenix numbers are very close to each other. 

However, with a hiking example and 6X measuring a lower average HR from the wrist vs the chest, the 6X looks low on calories compared to the others. 

So it appears that if the input data is the same then calories calculated is very close, which is good to see, but if the data measurements are wrong then so too are the calories, which is not surprising. 

I'm following up on that last post and the hiking profile discrepancies. I've also noticed that the recorded HR of my first hike with Fenis 6s Pro was lower than it should have been and the total calorie burn was very low (even for such heartrate I believe). Do we have to conclude that the hiking HRM at least is off and/or that the calorie algorithm is off too? how can that be possible? Is it better on the walking activity?

A lot can happen with Garmin firmware in two years since my post so who knows what the reality is today?

If I want accurate heart rate (e.g.cycling) I use a chest strap. If I'm less bothered (walking and hiking) then I make do with WHR. My interest is less in calories, more in fitness and performance, so I focus on different metrics.