Calorie Calculator

What is a calorie calculator?

A calorie calculator estimates how many calories your body burns in a day. Enter your sex, age, weight, height and how active you are, and it shows the calories you need to keep your weight the same, along with a range of targets for slow weight loss or gain.

Knowing this number is the first step of any nutrition plan. It stops you from guessing, and it gives you a clear starting point that you can adjust over the following weeks.

BMR vs TDEE: what is the difference?

Two terms appear in every calorie calculator, and they mean different things:

• BMR: Basal metabolic rate is the energy your body uses at complete rest for breathing, circulation, temperature control and cell repair.
• Activity: Walking, working, exercising and even fidgeting burn calories on top of your BMR.
• TDEE: Total daily energy expenditure is your BMR plus the calories you burn through activity. It is the number that matters for planning what to eat.
• Maintenance calories: This is another name for TDEE. Eating this amount should keep your weight steady.

The formula behind the calculator

Our calculator uses the Mifflin-St Jeor equation, which is widely used and is considered one of the more reliable estimates for healthy adults. For men, BMR = 10 x weight (kg) + 6.25 x height (cm) - 5 x age + 5. For women, BMR = 10 x weight (kg) + 6.25 x height (cm) - 5 x age - 161.

Here is an example. A 30-year-old man who weighs 80 kg and is 180 cm tall has a BMR of 800 + 1,125 - 150 + 5 = 1,780 calories. If he is moderately active, multiply by 1.55 to get a TDEE of about 2,759 calories a day.

Choosing your activity level

The activity multiplier is the part people most often get wrong, and most people overestimate how active they are. If you are unsure, pick the lower level.

• Sedentary (x 1.2): A desk job with little or no exercise.
• Lightly active (x 1.375): Light exercise or sport 1 to 3 days a week.
• Moderately active (x 1.55): Moderate exercise 3 to 5 days a week.
• Very active (x 1.725): Hard exercise 6 to 7 days a week.
• Extra active (x 1.9): Very hard exercise combined with a physical job, or training twice a day.

Calories for weight loss, maintenance and weight gain

Your weight changes according to energy balance. Eat about your TDEE to stay the same, a little less to lose weight and a little more to gain. A common rule of thumb says that about 7,700 calories equal 1 kg (3,500 calories equal 1 lb) of body fat, so a daily gap of 500 calories adds up to roughly 0.5 kg (1 lb) a week. Real results vary, because your body adapts as your weight changes.

Small steps of 250 to 500 calories a day are easier to keep up than a crash diet, and they are less likely to leave you tired and hungry. To gain weight, add 250 to 500 calories a day and combine it with strength training, so more of the gain is muscle. Very low-calorie diets should only be followed with medical supervision.

How accurate is a calorie calculator?

Treat the result as a well-informed estimate, not an exact measurement. Muscle mass, genetics, hormones, medicines and health conditions can all move your real needs up or down by a noticeable amount.

The best way to improve the estimate is to test it. Eat at your target for two to three weeks, weigh yourself under the same conditions, such as in the morning before breakfast, and watch the trend. If your weight is not moving as expected, adjust your calories by 100 to 200 and check again.

Tips for using your result

• Look at the trend, not one day: Weight changes by a kilogram or more from day to day because of water and food in your body.
• Focus on food quality: Protein, fibre, fruit, vegetables and whole foods keep you fuller than the same calories from sweets and snacks.
• Do not forget sleep and water: Poor sleep and little water make hunger harder to manage.
• Recalculate when you change: When your weight changes by about 5 kg, or your activity changes, run the numbers again.
• Do not copy someone else's number: Two people of the same weight can have very different needs.

Who should speak to a professional first?

This calculator is meant for healthy adults. If you are pregnant or breastfeeding, under 18, living with a medical condition, taking regular medicines or find that counting calories makes you anxious, speak to a doctor or a registered dietitian. They can give advice that fits your body and your situation.

Common calorie mistakes

• Overestimating activity: Choosing a higher level than you really have makes the target too high.
• Cutting too much, too fast: Very large deficits cause tiredness, lost muscle and rebound eating.
• Ignoring liquid calories: Juices, soft drinks, sweet coffee and alcohol add up quickly.
• Not weighing portions: Portions are often larger than people think, which makes tracking inaccurate.
• Expecting a straight line: Progress is uneven, so judge it over weeks, not days.

Why use our free calorie calculator?

• Complete answer: BMR, maintenance calories and four goal targets in one view.
• Metric and imperial: Enter kg and cm, or lb, feet and inches.
• Safety built in: Targets that fall below your BMR are flagged.
• Private: Your numbers stay in your browser and are never uploaded.
• Free: No signup, no limits and nothing to install.