This calculator is for informational purposes only. You should consult a healthcare provider before making any health decisions.
Whether you’re hoping to maintain your current weight, or to lose or gain weight, knowing the amount of calories to consume each day is an important piece of information to have.
Wondering, “How do I calculate my ideal calorie intake?” Lucky for you, there are loads of calorie calculators available online, most of which use one of several formulas that have been shown to be relatively accurate in predicting people’s calorie needs.
The beauty of these calculators is that they do the math for you; all you have to do is plug in information such as your height, gender and activity level, and you’ll be given unique daily calorie targets based on your goals.
How Many Calories Should You Eat Per Day?
Accurately estimating the amount of calories someone requires each day is not the simplest thing to do, since calorie needs depend on a number of factors, including: someone’s current weight, age, height, gender, level of physical activity, and if they recently lost or gained weight.
This means that there isn’t a simple “one-size-all” calorie recommendation that can be used for all women and men of the same height (as you’ll often see when reading when about calorie needs). In fact, even reliable calorie calculators are not 100 percent accurate, since each person’s body works somewhat differently when it comes to fat storage, muscle building, and so on.
It’s essential to take into account both an individual’s body composition and lifestyle when determining their energy (calorie) needs. Another factor to consider is if someone has recently dieted, since this can actually reduce how many calories they require. Someone’s metabolic rate and energy expenditure are likely to decrease if they’ve lost weight, which can make maintenance and further eight loss more difficult.
There are three different calorie numbers to keep in mind when using calorie counters: the amount you need to maintain your current weight, to lose weight or to gain weight. As you’d probably guess, gaining weight will require the most calories, while losing it will require the least.
Here are some terms to become familiar with when using calorie calculators:
- Basal metabolic rate (BMR), which is the amount of energy needed while resting in a temperate environment when the digestive system is inactive (after you’ve been fasting overnight). For most people, about 70 percent of total energy burned each day is attributed to their BMR, which includes all energy needs to fuel organs like the brain, muscles, liver, etc.
- Resting metabolic rate (RMR), which is similar to BMR. This is the number of calories you burn while you’re at complete rest.
- Total Daily Energy Expenditure (TDEE), which takes into account the calorie needed to maintain all of your bodily functions, plus the amount of physical activity you do. This is what you can consider your “maintenance calorie target.” It’s the best number to use when dieting or trying to build muscle because it includes your RMR, non-exercise activity thermogenesis (NEAT), calories burned from exercise and the thermic effect of food.
It’s useful to know your RMR/BMR, but this leaves out the calories needed for physical activity. Physical activity accounts for about 20 percent of energy expenditure on average, while about 10 percent is used for the digestion of food (also known as thermogenesis).
Therefore, knowing your TDEE can be very helpful. Once you know this number, a basic recommendation is to either add 500 calories per day to gain weight gradually or subtract 500 calories per day to lose weight slowly.
4 Proven Formulas to Estimate Calorie Needs
What’s the most accurate calorie calculator? There are four formulas that are most often used to estimate someone’s energy needs. Here is a brief descriptions of each:
1. Mifflin-St. Jeor Calculator
This formula is generally considered the most accurate for calculating BMR, but it doesn’t take into account an individual’s lean body mass or their physical activity level. One study found that “The Mifflin-St Jeor equation is more likely than the other equations tested to estimate RMR to within 10 percent of that measured for obese and non obese individuals.”
2. Harris-Benedict Calculator
This was one of the earliest calorie equations to be used, first introduced in 1984. Since then it’s been updated to be more accurate, and it’s still used by organizations such as the World Health Organization, but some feel that the other calculators are still more accurate since they take into account information such as muscle mass.
3. Katch-Macardle Calculator
This equation calculates your resting daily energy expenditure (RDEE), which takes your metabolic rate and lean body mass into account. This makes it unique compared to both the Mifflin-St Jeor and Harris-Benedict equations. Katch-McArdle is recommended most for people who are generally lean and know their body fat percentage.
4. Cunningham Calculator
This equation is used to calculate resting metabolic rate and has been found to yield acceptable estimates in muscular physique athletes. It’s recommended most for athletic and active adults.
How Many Daily Calories to Lose Weight?
How many calories should you eat to lose weight? To lose weight, you need to consume fewer calories than you burn each day. As mentioned above, you can roughly determine this number by taking your daily maintenance calories/TDEE number and subtracting 500.
The amount left is your target calorie intake each day. While it’s not a perfect formula, eating this amount can lead to slow weight loss, about 0.5 to 1.5 pounds per week on average. Note that because your exercise level is factored into your TDEE, you don’t need to further subtract calories burned by exercise.
When it comes to cutting calories in hopes of losing weight, it’s best not to go to extremes in terms of creating a very big calorie deficit. When you drastically cut your calorie intake you can initially lose some weight, but it’s a mix of muscle, fat and water/fluids that you’re losing, which isn’t necessarily beneficial.
The problem with losing muscle due to fad diets and extreme calorie deficits is that this decreases your metabolic rate, plus it can also interfere with athletic performance and general functionality. On top of this, muscle mass is what gives your body an attractive appearance and healthy, toned look, so you don’t actually want to get rid of it in hopes of simply watching the number on the scale go down.
Hitting a Weight Loss Plateau? (Is Losing Weight Slowing Your Metabolism?)
If you’ve recently dropped some weight, and now are noticing that it’s getting more and more difficult to maintain your lower weight or to keep losing, know that this is a real phenomenon and that you’re not just imagining it.
Losing weight means that you’ll require less calories just to maintain your current weight, since your metabolism adjusts to weight loss by decreasing your calorie needs/metabolic rate. This is sometimes called being in “starvation mode.”
Being in a calorie deficit can also naturally lead to less desire for physical activity, and may increase your appetite. All of these factors together mean that it can sometimes be hard to keep weight off.
How can you deal with this and prevent yourself from re-gaining the weight you’ve lost? Here are some strategies:
- Keep a daily journal of your meals/calorie consumption to get a good idea of what you’re actually consuming. You may not realize if you’re gradually starting to eat more, which can impact your results.
- Keep track of your workouts and physical activity, such as by using a fitness tracker band, so you can notice any changes in your routine. Tracking your steps taken can also indicate a slow down in general non-exercise activity as opposed to more strenuous workouts. Less activity overall means that you’ll require less calories, so keep this in mind.
- Pay attention to other factors such as stress and sleep. Both of these can cause changes to your metabolism, energy expenditure and appetite.
- Notice any changes in your macronutrient intake (protein, carbs and fats). Eating a higher proportion of protein is known to help control hunger and support maintenance of muscle mass, while fiber is also beneficial for keeping you full. Try to emphasize both of these while cutting out added sugar, refined grains, unhealthy oils and processed/packaged foods.
- Try calorie-cycling, or periodically doing “reverse dieting.” Because over time our bodies adapt to a lowered calorie level, it can give your metabolism a boost if you occasionally eat above your maintenance calories.
- Try not to lower your calorie intake by more than 500 calories below maintenance to prevent your metabolic rate from dipping too much.
How Many Calories to Build Muscle?
Both sufficient calories and protein are necessary to gain muscle. Putting on muscle requires that your body is receiving adequate calories which provides energy for protein synthesis, which means that being in a calorie deficit will make it hard to put on muscle mass.
Most people will need to eat at least their maintenance number of calories or more each day to gain muscle gradually, while also doing strength-training exercises. You can roughly determine how many calories you need to gain muscle by taking your TTEE and adding between 200 to 500 daily calories.
Another recommendation is to gradually increase calorie intake by 10 percent to 20 percent above your current daily calorie intake. The key is to go slow, stay consistent with resistance training and to keep track of your progress. This will let you know if it’s times to make changes, such as eating more or less. For the best results in terms of improving your body composition, aim to eat a clean diet with foods like grass-fed meats, eggs, fish, quality protein powders, vegetables, nuts and seeds.
*While this calculator provides an estimated caloric intake based on a number of factors, your nutritional needs may vary. Speak with a nutritionist or healthcare provider before you restrict your intake to ensure you’re choosing a diet that’s right for you.