Calorie Calculator
Free TDEE calculator using the Mifflin-St Jeor equation. Enter your stats and activity level to find your maintenance calories, then adjust for weight loss or gain.
Calculate your daily calorie needs (TDEE) and set a target for your weight goal.
Understanding how many calories you need every day is the cornerstone of nutrition planning. Whether you want to lose weight, build muscle, or simply maintain your current physique, knowing your Total Daily Energy Expenditure (TDEE) gives you the data you need to make informed dietary choices.
What Is TDEE?
Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns in a day, accounting for all activities — from breathing and circulation (your Basal Metabolic Rate) to walking, exercising, and even digesting food. TDEE is personalised: two people of the same height and weight can have very different TDEEs depending on their activity levels and body composition.
The key insight is simple:
- Eat at TDEE → Maintain your current weight
- Eat below TDEE → Lose weight (calorie deficit)
- Eat above TDEE → Gain weight (calorie surplus)
How This Calculator Works
This calculator uses the Mifflin-St Jeor equation (1990), the most widely validated formula for estimating Basal Metabolic Rate (BMR):
- Male: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
- Female: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
TDEE is then calculated by multiplying BMR by an activity factor:
| Activity Level | Multiplier | Description |
|---|---|---|
| Sedentary | × 1.2 | Office job, little or no exercise |
| Lightly active | × 1.375 | Light exercise 1–3 days/week |
| Moderately active | × 1.55 | Moderate exercise 3–5 days/week |
| Very active | × 1.725 | Hard exercise 6–7 days/week |
| Extra active | × 1.9 | Physical job or twice-daily training |
Goal Adjustments
Once TDEE is calculated, calorie targets are adjusted based on your goal:
| Goal | Adjustment | Expected Result |
|---|---|---|
| Maintain | ± 0 kcal | Stable weight |
| Lose (~0.5 kg/week) | −500 kcal | ~0.5 kg fat loss per week |
| Lose fast (~1 kg/week) | −1000 kcal | ~1 kg fat loss per week |
| Gain (~0.5 kg/week) | +500 kcal | ~0.5 kg mass gain per week |
| Gain fast (~1 kg/week) | +1000 kcal | ~1 kg mass gain per week |
Safety floor: For loss goals, the calculator enforces minimum intakes of 1200 kcal/day for women and 1500 kcal/day for men to protect against nutrient deficiencies.
Understanding Your Results
TDEE (Maintenance calories): This is the number of calories you should eat to maintain your current weight. It is your energy equilibrium point.
Target calories: The adjusted intake for your selected goal. If you are aiming to lose weight, this will be lower than TDEE. If you are gaining, it will be higher.
Daily deficit/surplus: The difference between your target and TDEE. A deficit of 500 kcal/day translates to approximately 0.5 kg of fat loss per week (since 1 kg of body fat stores roughly 7700 kcal).
Worked Examples
Example 1 — Weight maintenance: A 35-year-old woman, 68 kg, 165 cm, moderately active.
- BMR = 10 × 68 + 6.25 × 165 − 5 × 35 − 161 = 1375 kcal
- TDEE = 1375 × 1.55 = 2131 kcal/day
Example 2 — Weight loss: Same woman, goal to lose ~0.5 kg/week.
- Target = 2131 − 500 = 1631 kcal/day
Example 3 — Muscle gain: A 28-year-old man, 80 kg, 180 cm, very active.
- BMR = 10 × 80 + 6.25 × 180 − 5 × 28 + 5 = 1940 kcal
- TDEE = 1940 × 1.725 = 3347 kcal/day
- Gain target = 3347 + 500 = 3847 kcal/day
Tips for Hitting Your Calorie Goal
Track for accuracy: Research consistently shows people underestimate food intake by 20–40%. Use a food diary or tracking app for the first few weeks to calibrate your understanding of portion sizes.
Protein priority: Aim for 1.6–2.2 g of protein per kg of body weight. Protein preserves muscle during deficit phases and supports growth during surplus phases. It also has the highest thermic effect of food, meaning 20–30% of protein calories are burned during digestion.
Adjust by results: Your TDEE estimate is just a starting point. Track your weight weekly (same time, same conditions) and adjust calories by 100–200 kcal if your weight is not moving in the expected direction after 2–3 weeks.
Diet breaks: If dieting for more than 8–12 weeks, consider a maintenance period (1–2 weeks at TDEE) to reset hunger hormones and reduce metabolic adaptation. This can improve long-term adherence.
Frequently Asked Questions
How accurate is this calculator? TDEE estimates typically have an accuracy of ±10–20% compared to laboratory-measured values (via doubly labelled water or indirect calorimetry). Real-world factors like NEAT (non-exercise activity thermogenesis), gut health, sleep, and stress all affect actual calorie burn in ways that no equation can fully capture.
Should I exercise more to eat more? If you chose an accurate activity level, additional exercise is already factored in. If you significantly increase your exercise load, recalculate with a higher activity level.
Can I lose weight without counting calories? Yes. Many people achieve weight loss through food quality changes (eating more whole foods, less ultra-processed foods) without explicit calorie counting. However, understanding your rough calorie range helps you make better choices even without strict tracking.
What happens if I consistently eat at a deficit for months? Prolonged deficit causes metabolic adaptation — your body reduces TDEE by lowering BMR, reducing NEAT, and altering hormone levels (leptin, ghrelin). This is why weight loss plateaus occur. Periodic diet breaks, prioritising sleep, and resistance training all help counteract this.