what's a good heart rate monitor to use?

Really, it's the app that determines how well the calorie burn is estimated, and even then (as explained above) it's just an estimate. The intensity of your workout can affect accuracy too, HRM's tend to give more accurate results at higher intensities, for example. That said, it is better than most simple cookie-cutter calorie burn estimators like MFP or some formulas like "100 calories per mile running". Those don't work for everyone.

I have used two and love them both. First was a Scosche Rhythm which is worn on your arm. The main complaints people have with it is getting it in the right place, it will not give solid readings if the optical sensors are not over an area where it can get a good reading (duh). I had a blood draw done once and simply took note of where exactly on my arm they stuck me and started putting it there all the time. Never had a single problem, not even once after doing this.

Second and current one is a Wahoo Tickr X. I really like this one. It does not have to be paired with any device to track HR. If you use the Wahoo Fitness app it can even give you some XYZ axis info on your running form to help you figure out how you can run more efficiently in case you bobble around a whole lot, along with cadence which normally would require a separate foot pod, but the gyroscope in the chest strap HRM can pick up your stride saving you some bucks and having to strap on another device. I find the Wahoo Fitness app sucks on Android though (maybe they have fixed it since though). For Apple devices though the Wahoo Fitness ap is supposed to be rock solid however. You do not have to use the Wahoo Fitness app though, any device that can pair with a Bluetooth HRM or ANT+ can use it.

Loving my Fitbit charge HR!!

I use the Polar FT4 as well. I really love it.

glevinso wrote: »

Heart rate monitors are meant for tracking heart rate with the intention of using the information to determine training zones. There is a non-direct correlation between heart rate and calorie burn, however they are not necessarily something to be relied on. They can only give you a modest approximation of calorie expenditure, but by no means are they an absolute tool for measuring exercise output.

If your goal is to track calories expended you might be disappointed.

This^

sarahsloath wrote: »

Thank you for these very honest and. Informative answers. I would still like to have a HRM mainly out of the curiosity to find out how much energy I'm burning. I'm not a runner but love step workouts and other aerobics and sometimes use weights while doing these. Also I want to get my body fat down, I do not have much weight to lose so cannot rely on calorie counting alone.

That's the thing though, an HRM won't give you an answer for things like weights and aerobic classes. You would just be getting a random number based off of a formula used for steady state cardio. You could get just as close making an educated guess.

sarahsloath wrote: »

Oh OK I was hoping the monitor would really help to give me a closer idea. Still new to MFP, trying to get calorie input and output right when adding excersise!

Not for many exercises, no. That's why I asked up thread what activities you do the most.

If among your list you'd answered "running" then yes, a HRM is a useful tool, although heart rate data isn't strictly needed to provide useful calorie burn estimates.