Calories while walking/running

wreckage

What is the best way to determine actual calories burned on a walk/run. I use the MapMyWalk app on my phone, so I know pretty exact distance, time and speed. I've looked at a few different calculators on the web and seem to get insane variations. i.e - MFP says I'm burning 290 calories, while healthstatus.com has me at 438. I guess that brings me to my next question...
I know when you add in a cardio exercise on MFP it asks for minutes performed and calories burned. Does this save any type of calculation based on your weight/measurements, or is it using using the exact breakdown of calories as the person who entered it? For instance, if a 110 lbs female enters in some activity and says it is burning 4 calories a minute, does it take that same 1 minute to 4 calorie breakdown and apply it to me?

Sorry, i'm sure both of these questions have been asked before, but I found the search function flooded with results for my search terms.

Panda86

MFP works your weight into the equation for calories burned, so that its more tailored to you. I go with MFP. It's not 100% accurate, but its pretty close from my experience.

PLUMSGRL

It's based on the person who entered it- but I still think it's a ball park estimate.
Best way to guage is a HRM- most people like the Polar F6.
Happy Trails!

Lunarokra

Main reason why last night I bought the HRM. I use the MFP calories burned for now until I get the hang of the HRM.

rshunk

When I do my walk/runs I use my HRM. If I do additional walking without it I just go with what MFP calculates for me. I know that it is off, it underestimates for the most part from what I have seen, but I am ok with that from time to time!

wreckage

Wow, guess I need an HRM

I hadn't really noticed how hard MFP failed at the calculations until today. The difference between 3 mph, was like 100 cal less than 3.2 mph, but 3.5 mph was about 50 less than 3.2 mph. It confused me greatly.