Calorie Calculator
Estimate your daily calorie needs (TDEE) and get simple targets for keeping, losing or gaining weight.
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How many calories do you really need? The answer depends on your body and how active you are. This calorie calculator estimates your total daily energy expenditure (TDEE), the calories you burn in an average day, and turns it into simple targets for maintaining, losing or gaining weight.
How to use the calorie calculator
- Choose metric or US units.
- Enter your sex, age, height and weight.
- Pick the activity level that best describes a typical week.
You get your maintenance calories plus targets for mild weight loss, weight loss and weight gain. Your BMR, the calories you would burn resting all day, is shown for reference.
How the calculation works
The calculator works in two steps.
Step 1: basal metabolic rate. It uses the Mifflin-St Jeor equation, which research has found to be the most reliable for most adults:
Men: BMR = 10 × kg + 6.25 × cm − 5 × age + 5
Women: BMR = 10 × kg + 6.25 × cm − 5 × age − 161Step 2: activity. BMR is multiplied by an activity factor to give your TDEE:
| Activity level | Factor |
|---|---|
| Sedentary | 1.2 |
| Light (1–3 days of exercise) | 1.375 |
| Moderate (3–5 days) | 1.55 |
| Very active (6–7 days) | 1.725 |
| Extra active (physical job plus training) | 1.9 |
Step 3: goal. A pound of body fat stores roughly 3,500 kcal (about 7,700 kcal per kilogram). Eating 500 kcal a day below your TDEE adds up to 3,500 kcal a week, or about 0.5 kg (1 lb) of loss. A 250 kcal deficit gives about half that. A 500 kcal surplus supports gradual gain.
Worked example
A 35-year-old man, 180 cm tall and weighing 80 kg, who exercises four times a week (moderate):
- BMR = 10 × 80 + 6.25 × 180 − 5 × 35 + 5 = 1,755 kcal
- TDEE = 1,755 × 1.55 ≈ 2,720 kcal a day to maintain his weight
- To lose about 0.5 kg a week: 2,720 − 500 ≈ 2,220 kcal a day
- To gain about 0.5 kg a week: 2,720 + 500 ≈ 3,220 kcal a day
The calculator rounds results to the nearest 10 kcal, since nobody can measure food more precisely than that.
Why your real needs may differ
Any formula is based on averages. Your actual needs depend on muscle mass, genetics, hormones, sleep, stress and how much you move outside the gym, such as walking, standing and fidgeting. That last factor alone can differ by several hundred calories a day between two people of the same size.
Treat the result as a starting point. Eat at your target for two to three weeks, weigh yourself under the same conditions a few times a week, and adjust:
- Losing faster than planned? Add 100–200 kcal.
- Not losing at all? Subtract 100–200 kcal or add more daily movement.
Tips for reaching your goal
- Prioritise protein. It keeps you full and helps keep muscle while you lose fat. Many guidelines suggest 1.2–2.0 g per kg of body weight for active people.
- Do not cut too hard. Large deficits are hard to keep up and often lead to rebound weight gain.
- Recalculate as you go. As you lose weight, your TDEE falls. Update your numbers every 4–5 kg.
- Drinks count. Juice, alcohol and sugary coffee can add several hundred calories a day without making you feel full.
- Strength train. It helps the weight you lose come from fat rather than muscle.
This calculator provides general estimates and is not medical advice. If you have a health condition, are under 18, or are pregnant or breastfeeding, talk to a doctor or registered dietitian before changing your diet.
Frequently asked questions
How many calories should I eat to lose weight?
A common starting point is about 500 kcal a day below your maintenance calories, which leads to roughly 0.5 kg (1 lb) of weight loss a week. Smaller deficits are easier to stick to and help preserve muscle.
Which activity level should I pick?
Be conservative. Most people overestimate how active they are. If you work at a desk and exercise three times a week, choose light or moderate, then adjust after two to three weeks based on how your weight actually changes.
Why is there a minimum calorie level?
Very low intakes make it hard to get enough protein, vitamins and minerals and can lead to muscle loss. The calculator will not suggest less than 1,500 kcal for men or 1,200 kcal for women, which are widely used lower limits without medical supervision.
Why am I not losing weight on the suggested calories?
The result is an estimate, and individual metabolism varies by 10% or more. People also tend to underestimate what they eat. Track your intake carefully for a few weeks, and if your weight does not move, lower your target by 100–200 kcal.
Does this work for pregnancy or breastfeeding?
No. Energy needs change during pregnancy and breastfeeding. Ask your doctor or midwife for guidance instead.