# How Many Calories Does My Body Need?

We have spent some time on this blog talking about ways Wolfram|Alpha‘s nutrition and wellness data can be useful tools in your everyday life, such as by computing the nutritional value of your favorite recipe and identifying a healthy body weight. Some of you have since asked how you can use Wolfram|Alpha to understand your body’s caloric needs to maintain a healthy body. With all of the talk surrounding the latest fad diets and nutrition programs, information about our bodies’ basic needs often gets lost in the noise.

You can estimate your body’s daily caloric needs by computing your basal metabolic rate (BMR) within Wolfram|Alpha. Your BMR is the estimated number of calories (energy) your body expends when at complete rest—in other words, your daily caloric needs just to operate your vital organs, nervous system, muscles, and skin. BMR varies based on your age, gender, height, and weight, and needs to be recalculated whenever one of these factors changes. As your physical activity increases through routine movements, and exercise, the number of calories your body needs increases.

When you enter “basal metabolic rate” into the Wolfram|Alpha computation bar, you will be prompted to enter your gender, age in years, weight, and height. Wolfram|Alpha will then calculate the number of calories your body needs to perform vital functions daily, and list your estimated total daily energy expenditure for each of five basic activity levels. Below is an example of a BMR calculation for a 27-year-old male who weighs 154 pounds and is 5’8″ tall. The energy expenditure chart indicates that if he is moderately active, his body requires an estimated 2649 calories per day.

This is just one method of determining your body’s caloric needs and is only an estimate. In a future post, we’ll show you how to calculate your daily food intake in Wolfram|Alpha to help you stay on track to meeting your body’s nutritional needs.

It might be helpful for WA to define the variety of “sedentary”, “lightly active”, and so forth. Or perhaps link to the definitions.

Even better would be to calculate it! If I put in “calories burned swimming 3 hours a day”…! Such data tables exist, so that wouldn’t be too difficult!?

Entering just “metabolic rate” produces the same output, so why use “basal”?

Does not work for me. I enter those parameters in metric units and the “Energy expenditure” field stays blank…

What kind of formular are you using to calculate the BMR? There are quite a few formulas out there to calculate it, it would be nice to know which one you are using it, or even better choose the formula you want to use.

As the last comment, it’d be great to have an option to calculate physical activity.

Hi Joan,

Thank you for your feedback. To answer your question, we use the Harris-Benedict equations to predict BMR.

Thank you!

As the whole world uses the standardized metric units this form is pretty stupid…

You can enter metric units as well, W|A will understand them..

But if I enter “How Many Calories Does My Body Need?” as in the article mentioned W|A doesn’t know what i want. So much for the linguistic progress..

I stand corrected – works for metrics as well , apparently no output if you just enter your age without “yr”

This is about time somebody produced really good material on this subject.

Saving internet site to my favorites.

Whenever I try to change the gender, the application crashes.

This is a much more accurate calculator than most that I see online. Others rarely offer an age related calculation. I’ve often wished that there would be a calculator that projected weight loss from a current weight, when the body is fed a certain amount of calories. For instance, if I was to eat 500 calories less than my recommended allowance every day how long would it take me to lose 2 stone (plus different types of exercise).

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