How many calories should you eat per day?
The number of calories your body needs every day depends on who you are and what you do. Your age, gender, weight, height and activity level all play a role. Add your goal on top — losing weight, maintaining or gaining — and you arrive at your personal daily calorie target.
This calculator uses the Mifflin–St Jeor equation, the most accurate widely-used formula for estimating calorie needs. It first calculates your Basal Metabolic Rate (BMR) — the calories your body burns at rest — then multiplies it by your activity level to give your Total Daily Energy Expenditure (TDEE), and finally applies a deficit or surplus based on your goal.
Formula
Men: BMR = (10 × kg) + (6.25 × cm) − (5 × age) + 5 | Women: BMR = (10 × kg) + (6.25 × cm) − (5 × age) − 161 | Then: TDEE = BMR × activity multiplier
Calorie targets by goal
Your goal determines how many calories to eat relative to your maintenance level. The table below shows the recommended adjustments:
| Goal | Daily adjustment | Rate | Advice |
|---|---|---|---|
| Lose weight fast | −500 kcal/day | Fast loss | Sustainable if short-term. Monitor energy levels. |
| Lose weight | −250 kcal/day | Recommended | Gentle deficit — most sustainable for most people. |
| Maintain weight | ±0 kcal/day | Maintenance | Eat at TDEE level to hold your current weight. |
| Gain weight | +250 kcal/day | Lean gain | Gentle surplus — minimises fat gain while building. |
| Gain weight fast | +500 kcal/day | Fast gain | More mass gain but expect some fat alongside. |
Activity levels explained
Choosing the right activity multiplier is crucial — it has the biggest impact on your calorie target after your body size. Be honest: most people overestimate their activity level.
| Activity level | Multiplier | Example |
|---|---|---|
| Sedentary | × 1.2 | Desk job, minimal walking, no planned exercise |
| Lightly active | × 1.375 | Walking, light gym 1–3×/week |
| Moderately active | × 1.55 | Gym or sport 3–5×/week, active lifestyle |
| Active | × 1.725 | Hard training 6–7×/week or physical job |
| Very active | × 1.9 | Twice daily training, very demanding physical work |
What to do with your calorie target
Your calorie number is the foundation — but quality matters too. A 1,800 kcal diet of junk food and a 1,800 kcal diet of whole foods both hit the same number but have very different effects on hunger, energy and body composition.
Once you know your calorie target, the next step is splitting those calories into the right macronutrients: protein, carbohydrates and fats. Use our Macro Calculator to get those numbers instantly. Macro Calculator
Practical tip
Weigh yourself at the same time each morning (after waking, before eating). If your weight doesn't change after 2 weeks at your target calories, adjust by 100–150 kcal and reassess.
Limitations of calorie calculators
No formula predicts your exact calorie needs — individual metabolism varies by up to 15–20%. Treat the result as a starting point, not an absolute truth.
- •Metabolic adaptation: When you consistently eat less, your body adapts by burning fewer calories. This is why weight loss often slows after a few weeks.
- •Muscle vs. fat: More muscle mass means a higher BMR. The formula uses body weight but doesn't distinguish between muscle and fat.
- •Hormones: Thyroid function, cortisol and other hormones significantly affect metabolism and are not captured by any formula.
- •Food accuracy: Calorie labels on food are allowed to be off by up to 20%. Tracking is useful but never perfectly precise.
Remember
Never go below 1,200 kcal/day (women) or 1,500 kcal/day (men) without medical supervision. Extreme deficits cause muscle loss, fatigue and nutrient deficiencies.