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Weight loss calculator: How many calories do you need?

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If you are planning to lose weight then you should know how many calories per day you need to maintain a healthy weight. Studies have shown that calorie restrictive diets work extremely well, but only when they are followed! The problem with implementing a calorie restrictive diet is twofold:

  1. People often overestimate the amount of food that they require
  2. People underestimate the amount of restriction that is required

Below we share daily calorie tables and then provide advice on how to use this information to lose weight.

Remember that these are just average figures so you may require more or less than the calories stated here. If you wish to have a more accurate figure then read our page Basal Metabolic Rate (BMR) Explained. Both of these are good weight loss calculators.

Also, you only need the higher figure on the days that you are most active. Doing 2 intensive workouts each week does not mean you need maximum calories on the other 5 days. If you need help with developing a diet plan take a look at our personalized weight loss plan – we do all the hard work for you and provide you with support for the next 6 months. If you want to learn more about healthy weight loss start here: How To Lose Belly Fat, or carry on to the calorie tables below.


Daily Calorie Needs for Females

Important: these are averages and provide a guideline only.

Age/years Sedentary Low activity High activity
2-3 1100 1250 1400
4-5 1200 1350 1500
6-7 1300 1500 1700
8-9 1400 1600 1850
10-11 1500 1800 2050
12-13 1700 2000 2250
14-16 1750 2100 2350
17-18 1750 2100 2400
19-30 1900 2100 2350
31-50 1800 2000 2250
51-70 1650 1850 2100
71+ 1550 1750 2000

Daily Calorie Needs for Males

Age/years Sedentary Low activity High activity
2-3 1100 1350 1500
4-5 1250 1450 1650
6-7 1400 1600 1800
8-9 1500 1750 2000
10-11 1700 2000 2300
12-13 1900 2250 2600
14-16 2300 2700 3100
17-18 2450 2900 3300
19-30 2500 2700 3000
31-50 2350 2600 2900
51-70 2150 2350 2650
71+ 2000 2200 2500


How Many Calories Do You Need to Reduce By?

In weight loss studies carried out by health scientists, women who ate 1000 calories less than their daily requirement lost around 2 pounds per week. This is considered a healthy and sustainable level of weight loss. The same rule applies to men. So, how many calories should you be eating?
The following two tables show the average calories requirements for males and females at various ages for varying levels of activity, i.e. sedentary (no exercise, rarely active), low activity (walking, housework, some play) and high activity (regular exercise, generally more active in work and life).

This is a general guide to the amount of calories you need to be in deficit to lose a specific amount of weight:

  • If you are in a deficit of 500 calories per day you will lose approximately 1 pound per week
  • A calorie deficit of 750 calories will help you lose about 1.5 pounds per week
  • A calorie deficit of 1000 calories will help you lose about 2 pounds per week (about 1 kg weight loss per week)
  • To lose 20 pounds in a year you will need to eat 200 calories less per day than you were eating when your weight was stable
  • To lose 20 pounds in 1 month you would need to eat 2400 calories less per day (this is why very overweight people who have been eating around 4000 calories per day can lose weight quicker than lighter people, as they can reduce their intake by 2400 calories per day and still eat enough to sustain themselves).

Exercise Does Not Require Many More Calories

What often strikes people who are new to dieting and exercise is that the high activity group do not require many more calories than the low activity group. Being very active adds 300 calories for men and 250 calories for women (compared to low activity), although during the teenage years the difference is higher.

This is the equivalent of a sandwich or a large white coffee in terms of food energy. This is why it is very important that you do not eat more food just because you are exercising! The exercise creates a calorie deficit but if you eat more to compensate you will fail to lose weight.

We have included information on activity calorie burn (calories burned for different exercises) in our article on What is the Best Exercise to Help Lose Weight?

Calorie Requirements for Teenagers

We have highlighted the calories needs of teenagers as this is a very important time during a persons development, and also a time when many people start to become more aware of their bodies.

Few teenagers are aware that their calorie needs are higher than that of any other age group, and for very active teens, such as those that play sports or are practicing martial arts or are learning to dance, they need around 500-600 more calories a day than their sedentary peers.

Also during this time the quality of energy consumed must be high as there are many nutritional requirements for healthy growth and development. What is very worrying is the trend for many teens to skip meals to keep their weight down. They could be setting themselves up for long term health problems as well as stunted growth. We have a page dedicated to teenagers here: Diet and Weight Loss Advice for Teenagers.

Calorie Needs As We Get Older

For a woman in her 30’s that is not exercising, 2000 calories a day is enough to maintain weight. To lose 2 pounds per week she needs to reduce her daily calories by 1000, which means consuming 1000 calories a day. If she is exercising 3-4 times a week then she can eat 1250 calories per day.

This may seem low, but it is how our bodies work. To lose weight you need to restrict calories, this is what is meant by a calorie deficit. Eating healthier foods help too. Lean proteins will be used to build new muscle tissue. Fresh fruits and vegetables will contain fiber that aids digestion and are full of essential vitamins and minerals. However, bread is full of energy (around 100 calories per slice) and has little of nutritional value.

Losing weight is certainly not just about counting calories, it is about eating a balanced diet and exercising too. Remember, that diet without exercise almost always leads to eventual weight loss failure – see our article MotleyHealth’s Guide To Losing Weight to learn why.

Calories in Carbohydrates, Protein and Fat

a Calorie and Nutrition Label

Typical Calorie and Nutrition Label

If you are counting calories to aid weight loss, then knowing how many calories are in carbohydrates, proteins and fats can help you to calculate how much you need of each of the main food groups (macronutrients).

  • Protein has 4 Calories per gram
  • Carbohydrates has 4 Calories per gram
  • Fat has 9 Calories per gram
  • Alcohol has 7 Calories per gram

At first glance you may think that the best way to create an energy deficit is to eat more carbohydrates, but not all carbohydrates are equal. To lose weight while eating carbs you need to eat low GI carbohydrates (effectively they contain less sugar) which tend to have higher fiber content, which means that you do not absorb so much of the energy.

All food that you consume is either used immediately as energy by the body or it is stored as fat for the future. So, you put on weight when you eat more than you burn, you maintain your weight when you eat as much as you burn, and you lose weight when you eat less than you burn. Understanding this is the key to losing belly fat and losing weight.

If you look at the calories in fat, it quickly becomes obvious why there has been such an emphasis on eating low fat foods in recent decades. Fat has more than twice as many calories per gram than carbohydrate or protein. A healthy and well balanced diet will have adequate macro-nutrients and still allow weight loss to occur.

So swapping fatty food for carbohydrate or proteins means that you can eat the same weight in food and take in less calories. Unfortunately, the health food industry has taken advantage of this basic fact and produced many foods that are low in fat but far higher in sugars than traditional home cooked meals ever were. Read Sugar, Carbohydrates and Your Health to learn more about this.


Structure Your Life

To lose weight you need to start to structure your life. You need to plan what you are going to eat each day so that you do not end up snacking on junk food when your fridge gets empty. You need to plan each exercise session in advance so that you never put off exercising because you cannot think what to do.

Ideally you should have a list of 5 or so workouts that you enjoy following, whether they be bodyweight exercisescircuit training workoutsweight training workouts or just sessions on the elliptical trainer. This ensures that you can get variety in your new lifestyle and this helps you to stay interested.

If you plan your weight loss well, and understand the role of calorie restriction and exercise in losing weight, then there is no reason why you cannot lose 100 pounds in 2 years. It will not be an easy task, but it will be extremely rewarding, and possibly the best thing you ever do.

2 years may seem like a long time to wait, but this is really the only healthy way to lose 100 pounds, and it will fly by. You will also start to get fit and reduce your risk of many serious illnesses, such as diabetes, heart disease and stroke.

Create An Energy Deficit

If there is one rule that applies to every single overweight person it is this:

  • To lose weight you must create an energy deficit

It is really that simple! Although as we all know, implementing a theory is never as easy as writing it down.

The amount of energy you consume is entirely related to what you eat and drink. So the first step in losing weight is to determine how much you are eating and make a guesstimate at how much you need.

Permanent Lifestyle Changes

OK, simply eating less will work, but not as effectively as eating less and exercising. When you consistently eat less food than you need you are in an energy deficit and you will lose weight, but your metabolism will slow down, i.e. your resting metabolism rate will reduce.

This means that you will burn less energy throughout the day, which reduces your requirements even more, so you stop losing weight. Then you have to eat even less, and the cycle continues until a point where you are not receiving enough nutrients and vitamins to maintain a healthy body.

By exercising while dieting you keep your metabolism high and you build new muscle tissue which requires energy. By increasing your metabolism you can more easily adjust your diet slightly to make changes to your daily energy deficit.

It is recommended that you make permanent lifestyle changes that will help you lose weight at a steady rate. Generally it is advisable to aim to lose 1-2 pounds per week (0.5 – 1kg per week).

Do not forget that there are a lot of calories in alcohol, especially beer. Just a few beers a week can put you over your daily energy requirements and stop you from losing weight. For example, drinking one glass of wine per day is enough to add 14 pounds of weight over a year. One bottle of wine has as many calories as a large meal. So if you are serious about losing weight you need to ensure that you are losing weight every day of the week. This is why diets such as the Dukan Diet are so successful, because they encourage you to give up alcohol completely.

Calories Are Hard To Count

The order in which food is presented to you can determine how many calories you think it contains. If you are shown a low calorie fruit salad and then a burger you are likely to think that the meal contains more calories than if you see a burger followed by a high calorie cheesecake.

Research published in the Journal of Consumer Research explains that simply changing the order in which 2 meals were shown to a person would significantly alter their perception of how many calories were in that meal.

This discovery could explain why so many people eat too much food and put on weight, especially those that love desserts.

For example, when people were shown a cheeseburger they estimated that it contained 570 calories, whereas when shown a salad first and then a cheeseburger, they thought that the cheeseburger contained 787 calories. Just by looking at another meal they thought that the cheeseburger contained more energy than it actually did.

“The sequence in which items are considered often influences our evaluations of these items” – Alexander Chernev, Northwestern University.

Just by changing the order in which the meals were viewed changed the perceived calories from 757 to 1,097 calories.

Self Regulation of Consumption

This research suggests that understanding this principal can help people to self regulate their food consumption which should reduce overeating. If you are trying to lose weight then eating main courses and then desserts will probably result in you underestimating how much food you are eating, and you will fail to lose weight.

Diet is the main cause of obesity and weight problems, but many people do not realise that this is the case. Also, many people really think that they are not overeating even though their weight problem is clear evidence that they are.

So next time you are shopping or ordering a meal, look at the starters first and then the main meal and think about how many calories they contain. Maybe this will help you to determine how much you should be eating.

This could also explain why people that love desserts are more likely to be overweight. They simply underestimate the amount of food that they are eating.

Learn how to measure how many calories you have used or consumed.

1500 Calories a Day With Exercise

So if your aim is to lose 1 pound a week until you reach your 100 pound weight loss, then you should eat around 1500 calories a day and exercise on a regular basis.

Your diet should be healthy and balanced. This means you should avoid sugar and saturated fats, and instead eat mostly low GI vegetables, fresh fruits, lean meat, fish and drink mostly water, tea and coffee.

For exercise you should aim to walk for a minimum of 15 minutes every single day. Plus also perform a 30 minute workout 3 times a week, or as you get fitter you can do a shorter but more intensive workout 5-6 times a week. This helps you to maintain a higher metabolism and so burn more fat.

It is important to see your doctor before you start a weight loss plan that will see you losing so much weight. If you have not done any exercise for many years then it is wise to get some professional medical advice. Generally a walking program is suitable for most people that are very overweight.


“Semantic Anchoring in Sequential Evaluations of Vices and Virtues.” by Alexander Chernev. Journal of Consumer Research: February 2011. A preprint of this article can be found at http://journals.uchicago.edu/jcr.

More like this in the Weight Loss section

  413 comments for “Weight loss calculator: How many calories do you need?

  1. MotleyHealth
    October 11, 2015 at 9:35 pm

    Hi Stuart, start with daily walking and eat a simple, healthy diet. Healthy food is not really expensive – buy carrots, onions, cabbage, potatoes, and cook veg soups etc. “Health food” is expensive, healthy food is not – it is often cheaper than processed junk!

  2. willow Ramsey
    October 27, 2015 at 10:44 pm

    I am 13 and weigh 178 pounds and am overweight. I want to look good in my clothes. My mom doesn’t make that much money and it’s getting cold outside. I need some things it hints to loose weight but I wanna loose it quick with some moderate health and healthy packed lunches for school. What’s more important calories or carbs. Anyways thanks hope to see from u soon

  3. MotleyHealth
    November 11, 2015 at 10:14 pm

    Hi Willow, neither carbs or calories is most important – they are both equally important. You need a balanced diet with plenty of fruits, veg and pulses to provide most carbs, lean proteins from chicken, fish and eggs, some healthy fats. Check out our nutrition section.

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