It's easy to track how many calories you take in...but how can you figure out how many calories you burn? I can sorta tell how many calories I burn on my eliptical, but they say you burn throughout the day. I can work out for a half hour on my eliptical and burn about 250 calories. That is with working out...so I can't imagine that I can burn much more than that throughout the day when I'm sitting at my desk at work. So there is no way I can burn close to what I am taking in.....

Someone told me here, and I think they are right..that it's all just a guessing game. You just have to try different things and see what works.
I think those bodybugg things are supposed to be pretty accurate but they are too costy for me.

How do you know you're burning 250 calories when you're exercising? How many calories does breathing burn? Maintaining your body temperature? Digesting food? Watching tv? Thinking?

Just being alive burns quite a few calories. If it didn't - you wouldn't have to eat unless you moved. Even in a coma, nutrition needs to be provided.

How many calories will your normal activities burn? The amount that allows you to remain at your current weight, without either gaining or losing.

How much is that? Only trial and error can tell you that.

It isn't an exact number -it vary from day to day depending on so many variables that you can only guess and approximate.

But, approximation really isn't terribly difficult - you just take a stab at it. The scale will tell you if you're on the right track.

I am lucky, I have a bodybugg so it tells me how many calories out. my eliptical says 2x what my BB tels me. you can calculate your BMR (google it) ( just breathing) and get an idea of what your body burns and what you may be able to eat, everything else is gravy :-) like cooking, making the bed, laundry, walking to and from the car, treadmill, walk, etc.

My eliptical tells me how many calories I am burning. It just seems strange to me that I am working extra hard and I am only burning 250 calories for 30 min. When throughout the day I am supposed to burn more than I am taking in. If I am eating 1400 calories a day, and only burn 250 for 30 min of exercising, it seems impossible to burn 1400.

don't beleive the machine read outs, uneless you wear a HRM strap, it is only guessing based on an average.

and you are burning calories all the time just being we add in execcise and activity to burn MORE than our BMR so for your size if you burn 1500 (based on hight and weight (don't know your age) the eliptical calories are extra, 3500 extra calories burned is 1 lb and to lose 1 lb a week you need to burn an extra 500 cals over what you take in.
so if you take in 1400, you burn 1500 doing nothing, you brun an extra 250 on the eliptical and another 200 calories, moving around your job all day for 500 extra a day, you should be down a lb in a week.

One of the simplest ways that people guess their daily calorie output is with the Basal Metabolic Rate (BMR) formula... this estimates how much you'd burn each day if you're sedentary, based on your age, height and weight. Then there are "activity factors" that you can multiply your BMR by to come closer to guessing how much you burn each day.

They're all over the internet, one is at http://www.caloriesperhour.com/index_burn.php (click on "BMR & RMR Calculator"). Like everyone has said, though, this is just a guess! There are certainly a lot of things affecting it.

I think you're selling your body short. It takes a lot of energy to keep the lungs constantly expanding and contracting... pump blood through something like 50,000 miles of blood vessels... physically push food/waste through 25 feet of intestines... replenish dying cells... maintain your immune system... keep yourself a constant temperature... etc.

All of these technologies are fairly primitive and not particularly accurate. The actual variance is tremendous.

There are so many factors that can affect calorie burn rates (and many of those factors are currently unmeasureable - at least outside the laboratory setting).

The BMR calculators are also notoriously inaccurate. I found them fairly accurate in high school, nearly 30 years ago) and increasingly less accurate over the years. The only good that came out of them, was my math skills (because this was before the BMR's were computerized, you had to calculate them based on forumulas calculating your height, weight, age, and activity level (which are all based on averages, not on what your body actually does).

I do suspect that dieting DOES lower metabolism, just from the difference in what the BMR calculators say I "should" be losing based on my calorie intake. When I was in my teens, I lost about what the calculators predicted, but gradually over time, I found that I lost less and less in comparison to the prediction. Now, I lose about 1/4 of what the calculators say I "should" be losing.

Thank you all. I would love to lose 1-2 pounds a week. We'll see how it goes.

Doesn't seem so off - if you burned 250/30min all day long, you'd burn 12,000 calories. Even just half that (125 cal/30min) would be 6000 cal/day. Burning 500 cal/hr is a pretty good clip.

I also use a bodybugg to track, but it's all individual...that's why a standard calculation isn't accurate. What I burn an hour on the elliptical will be different that what you burn.

To give you an idea, when I'm sleeping I burn about 1 cal per min. When I am awake and sedentary it's around 1.2-1.6 cal/min. When I am walking or moving around (cooking, etc) I burn around 2-2.5 cal/min. When I am very active/sweating it out on the treadmill or working out I burn from 6-10 cal/min.

A heart rate monitor with that counts calories is a bit cheaper than a body bug, and can also be quite accurate. You can wear some brands all the time (though they are a bit uncomfortable).

I get the best maths when I calculate my BMR multiply it by 1.2 (as my job is fairly sedentary) and then add on the calories burn during exercise according to my heart rate calories. When I calculated everything for a month, I was out by only about 0.2kg (0.5lb).