Is this the most accurate treadmill calorie burn calculator?

chetfreeman

MFP's exercise database doesn't provide an estimate of the amount of calories burned on a treadmill. Upon researching I found part of the reason is that the burn rate is very dependent upon one's weight - which makes sense. It takes less energy to move 140 pounds than 200. The incline also makes a difference. A website provided this formula:

The general formula for calories burned while running is as follows: Minutes spent running * (MET*3.5*weight in kg)/200.

If you do not know what your MET (Metabolic Equivalent of Task) is, use this formula to derive it: MET=[(0.2*Speed)+(0.9*Speed*%Grade)+3.5].

Grade is in degrees and is usually between 0 and 15 and likely set between 0 and 4. Speed is in miles per hour.

I found a website that seems to allow inputting the key factors. Is it the most accurate? http://42.195km.net/e/treadsim/

It seems to come very close to what I manually calculate using the above formula but I do not know if the formula is correct.

MPH shows 464 burned on a 4 mph walk for 63 minutes. I forget what my treadmill calculates, but it is much higher and closer to what the formula or the website produce (754 - 787).