There is no single “right” number of calories for everyone. A tall, active man and a shorter, less active woman can have daily needs that differ by more than 1,000 kcal.
The good news is that you can get a sensible estimate in a few minutes, and then fine-tune it by watching how your weight responds over a few weeks.
What is a calorie?
A calorie is a unit of energy. The “Calories” on food labels are kilocalories (kcal) — the energy needed to raise one kilogram of water by one degree Celsius. In many countries labels also show kilojoules (kJ); 1 kcal equals 4.184 kJ.
Your body uses this energy for everything from keeping your heart beating to walking up stairs. When you consistently eat more energy than you use, the surplus is stored; when you eat less, stored energy is used.
The three parts of your daily calorie needs
- Basal metabolic rate (BMR): the energy used at rest to keep you alive — usually the largest share. Read more in What is BMR?.
- Activity: planned exercise plus everyday movement such as walking, standing and household tasks.
- Digestion: the thermic effect of food — roughly 10% of what you eat.
Together these make up your Total Daily Energy Expenditure, or TDEE. We explain it in detail in What is TDEE?.
How to estimate your calorie needs
Example: a 35-year-old woman, 165 cm and 65 kg, who exercises three to four times a week. BMR ≈ 10 × 65 + 6.25 × 165 − 5 × 35 − 161 ≈ 1,345 kcal. With a moderate activity factor of 1.55, maintenance is about 2,085 kcal/day. A 500 kcal daily deficit gives a starting target of about 1,585 kcal/day for gradual weight loss.
Typical daily calorie ranges
The Dietary Guidelines for Americans give broad estimates for adults, depending on age and activity:
| Group | Approximate daily calories |
|---|---|
| Adult women | about 1,600 – 2,400 kcal |
| Adult men | about 2,000 – 3,000 kcal |
These are population averages. Your own estimate may sit outside these ranges, especially if you are very tall, very active or have a larger or smaller body.
Calories for weight loss, maintenance and gain
- Maintain: eat close to your TDEE.
- Lose weight gradually: a deficit of about 250–500 kcal per day is a common, moderate starting point.
- Gain weight or muscle: a surplus of about 250–500 kcal per day, combined with strength training.
A popular rule of thumb says a 500 kcal daily deficit leads to about 0.5 kg (1 lb) of weight loss per week. In practice, progress is usually slower over time as your body adapts, so use this as a rough guide rather than a promise.
Adjusting your estimate
- Stick to your target for two to three weeks.
- Weigh yourself a few times a week under the same conditions and look at the weekly average.
- If the trend is not what you expected, change your intake by 100–200 kcal per day and review again.
What you eat still matters. Enough protein, plenty of vegetables and fibre, and a sensible balance of macronutrients make a calorie target easier to stick to.
Try the calculators
Put this guide into practice with a free estimate.
Frequently asked questions
How many calories should I eat to lose weight?
Start with your estimated maintenance calories and subtract about 250–500 kcal per day. Adjust after two to three weeks based on how your weight actually changes.
Do I need to count calories?
Not necessarily. Counting can help you learn about portions, but many people manage their weight well by focusing on regular meals, protein, vegetables and fewer ultra-processed foods.
Why am I not losing weight on my calorie target?
Calorie estimates are averages and food tracking is often less accurate than we think. Water retention can also hide fat loss for a while. Review your intake over a few weeks and adjust gradually.
Methods and sources
- Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241–247.
- Frankenfield D, et al. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. J Am Diet Assoc. 2005;105(5):775–789.
- Dietary Guidelines for Americans, 2020–2025 (estimated calorie needs) (opens in a new tab)