- Calories are the energy in food. Eat less than you burn and you lose weight. Eat more and you gain.
- You can work out your daily intake from your basal metabolic rate (BMR) and activity level. The formula and an example are below.
- You don't have to weigh every bite. Consistency beats perfect accuracy.
- Besides calories, keep an eye on protein, carbs and fat (macros). Protein keeps you full and helps you hold on to muscle.
Counting calories is a simple idea: you work out how much energy you need and log how much you get from food. The trouble starts in practice. Many people give up after a week because logging meals wears them out. This guide shows an approach that works even without a food scale and spreadsheets.
Why calorie counting works
Your body needs energy to breathe, digest, move and keep its temperature steady. It gets that energy from food, measured in kilocalories (kcal). If you take in less energy than you use over a long period, your body draws on its reserves. This is called a calorie deficit. It's covered in more detail in the guide Calorie deficit: how to calculate it.
Above all, counting calories gives you a clear picture. Many people underestimate how much they really eat, especially oils, sauces, drinks and little snacks throughout the day. Logging shows you where the calories hide, and then you can decide what to do without guilt.
How many calories you need per day
Your daily need has two parts. The first is your basal metabolic rate (BMR), the energy your body uses at rest. The second is the movement you do during the day. Multiply your BMR by an activity factor and you get your TDEE, your total daily energy expenditure.
You can estimate BMR with the Mifflin-St Jeor formula:
- Men: 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
- Women: 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
Then multiply the result by an activity factor:
| Activity level | Description | Factor |
|---|---|---|
| Sedentary | Desk job, very little movement | × 1.2 |
| Lightly active | Light exercise 1 to 3 times a week | × 1.375 |
| Active | Exercise 3 to 5 times a week | × 1.55 |
| Very active | Intense exercise almost every day | × 1.725 |
A woman, 32 years old, 168 cm, 72 kg, lightly active. BMR = 10 × 72 + 6.25 × 168 − 5 × 32 − 161 = 1,449 kcal. TDEE = 1,449 × 1.375 ≈ 1,990 kcal per day. At this intake she would roughly maintain her weight.
This is an estimate, not exact science. Your real needs vary with genetics, body composition and everyday movement. Treat the result as a starting point and adjust it after 2 to 3 weeks based on how your weight changes. You can also get a quick result in the calculator on the home page.
How to start in five steps
- Find your needs. Calculate your TDEE or let the app recommend a target.
- Pick a goal. Maintain, lose or gain weight. For weight loss a mild deficit is enough, for example 300 to 500 kcal a day.
- Log everything you eat and drink. Including the oil in the pan, milk in your coffee and sweetened drinks.
- Watch the trend, not a single day. Your weight moves with water, salt and digestion. Look at the average over 7 to 14 days.
- Adjust after two weeks. If the scale isn't moving, eat a little less or move more. If it drops too fast, eat more.
Macros: protein, carbs and fat
Calories are the sum of the energy from three nutrients. It helps to know how much energy each one has:
| Nutrient | Energy per 1 g | What it does for you |
|---|---|---|
| Protein | 4 kcal | Muscle, recovery, feeling full for longer |
| Carbs | 4 kcal | Main fuel for your brain and movement |
| Fat | 9 kcal | Hormones, vitamin absorption, flavor |
| Alcohol | 7 kcal | Energy with no nutritional value |
Fat has more than double the calories per gram, so one extra spoonful of oil is enough to shift your budget. You don't need to hit an exact ratio. When losing weight, a sensible foundation is often said to be enough protein at every meal. For specific numbers, though, a doctor or dietitian can advise you best.
How to log food without weighing it
The biggest enemy of calorie counting is how tedious it is. Here are three ways to speed up logging a lot:
- Barcode. For packaged foods it's the most accurate option, and the app pulls the values in by itself.
- Food photo. Snap your plate and AI estimates the dishes, portions and calories. You can edit the result before saving. Learn more in the guide AI calorie counting.
- Repeat meals. Log what you eat often once, then add it again with a single tap.
In Caloora you can photograph your plate, scan a barcode or describe a meal in words. Free to start, no weighing needed.
Try Caloora freeMost common calorie counting mistakes
- Forgotten drinks, oils, sauces and "just a taste" while cooking.
- Inaccurate portions. It's easy to pour twice as much rice as you think.
- Strict weekdays followed by a "blowout" weekend that eats the whole weekly deficit.
- Eating too little. Your body will let you know with fatigue and sugar cravings.
You'll find a fuller list with tips in the article The 7 most common calorie counting mistakes. You can look up the values of everyday foods in the calorie database.
Who calorie counting isn't for
If you have an eating disorder, or have had one in the past, counting calories can do you harm. Be careful too if you are pregnant or breastfeeding, are under 18, or have a condition where diet matters. In these cases, talk to a doctor or dietitian first.
Even when counting suits you, you don't have to do it for life. For many people a few weeks is enough to get a feel for portions and mixed dishes. After that they move on to a looser routine.
Frequently asked questions
Do I need to count calories to the exact gram?
No. Consistency and honest logging matter more than perfect accuracy. Even an estimated portion gives you a useful overview if you do it over the long term and in a similar way each time.
How many calories should I eat to lose weight?
Subtract a mild deficit from your daily needs (TDEE), for example 300 to 500 kcal. A faster pace is harder to sustain and makes it more likely you'll eat more than you intend. You'll find the method in the calorie deficit guide.
Is it better to count calories or macros?
Calories are enough to start. Add macros once counting feels natural and you want to improve what you eat, especially your protein intake.
Can you count calories from a photo of food?
Yes, AI can estimate both the food and the portion from a photo. It is an estimate, though, so for more complex meals check it quickly and adjust. For packaged foods a barcode is more accurate.
How long should I count calories?
A few weeks is enough to get a feel for portions and what's in your meals. After that you can count only now and then, or when your goal changes.
The information on this page is general and educational. It does not replace advice from a doctor, dietitian or trainer. If you have a health condition, take medication, or are pregnant or breastfeeding, talk to a professional before changing your diet or exercise.