The Harris-Benedict Formula

Uses gender, but NOT lean body mass. This is the best choice for most average people

The Katch-McArdle Formula

Uses lean body mass, but NOT gender. This one works well for the more athletic types.
If you guessed at your body fat percentage this score won’t be accurate.

More about the BMR Calculator and some recommendations

Okay first a small rant…

Far too often I hear people say that BMR and calorie tracking is nonsense or some new fad diet comes along and says “No More Calorie Counting!”. Well, sorry to say it, but it’s all a bunch of B.S.!

For a very small percentage of people calories work differently due to some genetic defect or chronic disease. For the rest of us though these principals work just fine.

Some will discount it by saying that calorie quality is more important. True, if you ingest 5,000 calories all from fat you’re going to get quite fat,  but even if you eat 5,000 of pure protein you’re still going to get fat maybe just not quite as much simply because some of it will get used elsewhere in your body.

Don’t over-complicate things. Figure out what your calorie needs are and get those calories from quality balanced sources. If you want to eat more, move more. If you want to move less, eat less.

…rant over.

What exactly is BMR (Base Metabolic Rate)?

Your body burns calories all day no matter what you are doing. It needs energy to maintain itself and run your vital systems. So your Base Metabolic Rate (BMR) is the number of calories it would take to run your body all day while laying on your bed doing nothing. There’s a lot more awesome geeky information on it at Wikipedia so I won’t go into a bunch more detail here.

The BMR calculator on this page does the calculation and also asks for your normal activity level. It multiplies by a corresponding factor to give you and idea of how many calories you need to consume in order to run your body without gaining or losing any weight.

Some Recommendations Base On Your BMR Calculator Results

Whether your trying to get in shape by losing a few pounds or training hard and need to gain a few pounds it’s recommended to only change your weight by 1 or 2 pounds per week. We know that it takes 3500 calories equal 1 pound of body weight so planning your eating and exercising is easy once you know your BMR.

The BMR Calculator simply subtracts 500 calories for the lose weight column and adds 500 for the gain weight column. 500 calories x 7 days = 3500 calories (or 1 pound) per week. Easy right?

For example, I’m 6 foot 1 inch or 73 inches tall, weight 200 lbs, have about 15% body fat and am 40 years old. I’m not training to hard right now so I just put Moderate activity which puts my BMR at 3054.

So if I want to lose 5 pounds all I have to do is raise my activity level to burn an extra 500 calories or eat a little less to get my intake down to about 2500 calories per day. In five weeks I will be at my target weight. I know that sounds slow, but eliminating 500 cals per day is pretty painless. You can be more aggressive and get faster results by changing as much as 1000 calories, but it gets harder to stick to.

To summarize…

  • Use the BMR Calculator to get your calorie needs
  • Increase your activity to burn 500 to 1000 more calories, or…
  • Adjust your eating plan to consume between 500 and 1000 fewer calories, or…
  • Some combination of the two (eat a little less and run a little further)
  • Make changes gradually. Lower your calories by 100 per day for 5 days instead of all at once
  • Stick to your new workout / eating plan until you achieve your goal
  • Re-calculate your BMR and gradually adjust and go into maintenance mode

There you have it. It’s a pretty simple concept and I’ve probably made it much more long winded than need be, but it’s important that you understand how simple and effective it is. I hope you find our BMR calculator useful and let us know if you would like to see anything added to it.

To Your Health,