There are many factors that determine your body’s calorie needs, and every individual is different. Calories are nothing more than the energy your body uses for things like sleep, breathing, completing day-to-day tasks, and any other activity. This calorie calculator, based on the Mifflin-St Jeor equation, takes into account details like your age, height, weight, and activity level to help give you an estimate of your daily calorie expenditure.
How is this information useful? Whether you’re aiming to shed body fat, maintain your current weight, or gain muscle, it can help to have an idea of where you should be calorie-wise so you can match your energy intake (or food) with your health goals.
Understanding Calories
First, let’s talk calories. Scientifically speaking, losing body fat is attained through being in a calorie deficit, meaning the calories your body uses must be greater than the total number of calories you consume. Conversely, if your desire is to gain weight, you must take in a surplus of calories (i.e., eat more than you actually need).
With that said, when it comes to changing your body composition, what you eat can be just as impactful as the calories themselves. I’ll elaborate in the section below.
The Caveats of Calorie Counting
Calorie counting is one way you can reach your body composition goals, and this calculator can help. But it’s not always the best method for maintaining long-term results. Let’s address three main issues with calorie counting:
- Accuracy is difficult. A food’s calorie content can vary based on whether it’s served raw or cooked, how it’s measured, and the calorie app used. Logging how a food is prepared is just as essential as logging how much was eaten. Furthermore, most people underestimate how much of a food they have actually consumed (unless they are really measuring everything). So, while tracking calories certainly does work, most tracking is far from perfect.
- The quality of your food is more important than the calories. Focusing too highly on calories alone makes it easy to forget that the quality of your food can impact fat loss just as much as the calorie content. High-quality whole foods help keep blood sugar levels stable and promote satiety. Added sugars and processed foods may “fit” within your daily target, but they can actually cause more cravings, making it difficult to stick to a plan.
- Restricting calories may cause anxiety around food choices. Overrestriction can cause stress and promote behaviors that cause more harm than good. Obsessing over every calorie consumed can cause anxiety and guilt about certain food choices. This is the opposite of what we hope to achieve in improving our health.
Why Use a Calorie Calculator
Having an estimate of your calorie needs in combination with a good understanding about the calories (energy) in your food empowers you to set realistic health goals. Doing so for a short time (ideally less than 3 months) can educate you about where you might need to make certain dietary adjustments. For example, you may be surprised when you find out that your “healthy” morning smoothie is packed with several hundred more calories than you thought. Or perhaps you need to gain weight, and your calculations reveal that you are eating much less energy than your body burns each day.
This chart helps determine the average number of calories per day required to maintain your current body weight based on your activity level and many other factors. You can then make suggested adjustments to your calorie needs based on your health goals.
How to Calculate Your Body’s Calorie Needs
Use one of two methods to help you figure out your calorie expenditure. The first is a Calorie Calculator. Just plug in your information and get your results instantly. The second is a simple formula you can use to do your own calculation.
Just keep in mind this will only provide an estimate. It is important to consult with your health care provider before making decisions regarding any changes you make to your diet.
Calorie Calculator:
This Calorie Calculator does the work for you; simply enter your information, and it will quickly give you an estimate of your calorie needs. Optionally, you can use the formula below. Both are based on the Mifflin-St Jeor equation.
Calorie Formula:
The following chart is based on Mifflin-St Jeor Equation converted to imperial measurements. Since energy needs differ among men and women, there are different calculations for each. This is designed for healthy men and women, ages 19 years and older.
Step 1: Determine your REE (Resting Energy Expenditure). Calculate your Resting Energy Expenditure using this formula:
Men: REE = (4.536 x weight in lbs) + (15.88 x height in inches) – (5 x age) + 5
Women: REE = (4.536 x weight in lbs) + (15.88 x height in inches) – (5 x age) – 161
Example:
Woman: 150 lbs, 5 ft 5 in (convert to 65 inches), age 34
REE = (4.536 x 150 lbs) + (15.88 x 65 inches) – (5 x 34 yrs) – 161
REE = 680.4 + 1032.2 – 170 – 161
REE = 1381.6
(Metric conversion: To convert kilograms to pounds, multiply kilograms by 2.2. To convert centimeters to inches, divide centimeters by 2.54.)
Step 2: Select a Physical Activity (PA) Factor. Choose a Physical Activity Factor based on your activity level throughout the week:
| Activity | PA | Typical Living: Choose a Physical Activity Factor based on your activity level throughout the week. |
| Sedentary | 1.2 | Little or no exercise |
| Low active | 1.375 | Light exercise 1-3 days per week |
| Active | 1.55 | Moderate exercise 3-5 days per week |
| Very active | 1.725 | Hard exercise 6-7 days per week |
| Extremely active | 1.9 | Daily vigorous exercise |
Step 3: Determine TEE (Total Energy Expenditure)
Multiply REE (step 1) times PA Factor (step 2) to obtain the estimated TEE (calories per day) to maintain weight.
REE (step 1) x PA Factor (step 2) = TEE
Example:
REE (1381.6) x PA Factor (1.375)
1381.6 x 1.375
TEE = 1899.7
(Estimated calories per day to maintain weight)
Step 4: Adjust Based on Your Goal
- If fat loss is desired, subtract 300 – 500 calories per day to obtain adjusted caloric intake required to achieve weight loss of approximately 0.5 – 1 pound per week.
- For maintenance, use your TEE (step 3) to base your caloric intake on.
- If weight gain/bulk is your goal, add 300 – 500 calories per day to obtain adjusted caloric intake required to achieve weight gain of approximately 0.5 – 1 pound per week.
Example:
TEE (1899.7) – 500 calories per day
Adjusted amount: 1399.7
(Estimated calories per day to lose one pound per week)
Next Steps
Remember to monitor your results for at least one month, and adjust your daily calories as necessary. If you are interested in tracking your calories, try the free version of the Cronometer app.
Check out our growing library of delicious, high-protein, plant-based recipes that take the guess work out of calorie counting. Each simple recipe includes the calories and protein content per serving, making it easy to stay on track.
The information provided in this post is for informational purposes only and is not intended to serve as a substitute for medical advice. Contact your health care provider before making any decisions regarding your health and diet.
