Calorie Calculator
Calorie Calculator
How Many Calories Should I Eat?
Get your exact daily calorie target, BMR, TDEE, and personalised macro split for weight loss, maintenance, or muscle gain. WhatsApp share and free PDF report included. Based on the Mifflin-St Jeor equation.
How Many Calories Should I Eat Per Day?
Your calorie needs are unique to you. Two people of the same age and gender can have calorie needs that differ by 500-800 calories per day based on differences in muscle mass, activity level, and metabolic health. This is why personalised calculation -- rather than generic advice -- is essential for effective nutrition planning.
The number you calculate represents your Total Daily Energy Expenditure (TDEE) -- the total calories you burn in a day. Eating at this level maintains your weight. Eating below this level creates a calorie deficit and promotes fat loss. Eating above this level creates a surplus that supports muscle growth when combined with resistance training.
BMR vs TDEE -- What is the Difference?
Think of BMR as your engine idling when parked -- just keeping systems running. TDEE is your total fuel consumption for a full day of driving. For most moderately active adults, TDEE is approximately 1.5 to 1.7 times their BMR. Someone with a BMR of 1,600 calories and a moderate activity level would have a TDEE of approximately 2,480 calories per day.
The gap between BMR and TDEE is why activity level matters so much. A sedentary person burns their BMR multiplied by just 1.2, while a very active person burns their BMR multiplied by 1.725. This means the same person could need 500-800 more calories per day simply by changing from a sedentary to an active lifestyle -- even without changing any foods. Check your Calories Burned Calculator to understand how much specific activities add to your daily burn.
The Mifflin-St Jeor Formula -- How This Calculator Works
This calculator uses the Mifflin-St Jeor equation, developed in 1990 and recognised by the Academy of Nutrition and Dietetics as the most accurate BMR formula available for most people. It predicts resting metabolic rate within 10% accuracy for approximately 80% of the population -- significantly better than the older Harris-Benedict formula it replaced.
For Men: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) + 5
For Women: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) - 161
Your BMR is then multiplied by an activity factor: Sedentary (1.2), Lightly active (1.375), Moderately active (1.55), Very active (1.725), or Extra active (1.9). This gives you your TDEE. Your goal adjustment is then applied -- minus 500 for weight loss, plus 400 for muscle gain, or zero for maintenance.
It is important to understand that this is an estimate. Real-world metabolic rates can differ from calculated values due to individual variation, hormonal factors, medication effects, and adaptive thermogenesis. Start with the calculated number, track your weight for 2-3 weeks, and adjust by 100-200 calories if weight is not moving as expected.
Calorie Deficit for Weight Loss
A calorie deficit means consistently eating fewer calories than you burn. The fundamental principle is straightforward: one pound of body fat contains approximately 3,500 calories. A daily deficit of 500 calories therefore produces approximately 1 pound (0.45 kg) of fat loss per week. Our Weight Loss Calculator gives you a complete timeline showing exactly when you will reach your goal weight.
However, the relationship is not perfectly linear. As you lose weight, your BMR decreases (because there is less of you to fuel), and your TDEE decreases. This means you need to recalculate your calories every time you lose 5-10 kg to account for your new, lower calorie needs. Failing to recalculate is one of the most common reasons weight loss stalls after an initial period of success.
Avoid deficits larger than 25% of your TDEE. Extreme restriction triggers adaptive thermogenesis -- your body lowers its metabolic rate to conserve energy -- and causes disproportionate muscle loss, making both the deficit less effective and long-term weight maintenance harder. A deficit of 500 calories is sustainable; 1,000+ calories per day is not recommended for extended periods without medical supervision.
Check your BMI and Body Fat percentage alongside calories for a complete picture of your weight management status. Poor sleep dramatically increases hunger hormones and makes calorie deficits much harder to sustain -- check our Sleep Calculator to optimise your sleep.
Calorie Surplus for Muscle Gain
Building muscle requires a calorie surplus -- eating more than you burn so that your body has the energy and nutrients to build new muscle tissue. However, the size of the surplus matters enormously. A common misconception is that "more is better" -- in reality, muscle can only be built at a specific rate regardless of how large the surplus is. Excess calories above what muscle synthesis requires are simply stored as fat.
Research suggests a surplus of 300-500 calories per day is optimal for most people. This supports maximum muscle protein synthesis while minimising fat gain. Larger surpluses -- sometimes called "dirty bulking" -- primarily add fat, not additional muscle. Pair your calorie surplus with a protein intake of 1.6-2.2g per kg of bodyweight and progressive resistance training 3-4 times per week. Our Macro Calculator can help you dial in the exact protein, carbohydrate, and fat targets for muscle building.
Understanding Your Macros
Macronutrients -- protein, carbohydrates, and fats -- are the three energy-providing nutrients. Each plays a distinct role:
- Protein (4 calories per gram): Essential for muscle repair, immune function, enzyme production, and satiety. During a calorie deficit, adequate protein (1.6-2.2g per kg of bodyweight) is the single most important factor for preserving muscle mass.
- Carbohydrates (4 calories per gram): The body's preferred energy source, particularly for the brain and high-intensity exercise. Low-carb diets can work for weight loss but are not superior to moderate-carb approaches when protein and total calories are equated.
- Fats (9 calories per gram): Essential for hormone production (including testosterone and oestrogen), fat-soluble vitamin absorption (A, D, E, K), and cell membrane integrity. Never cut fat below 20% of total calories -- this impairs hormonal health.
For weight loss, our calculator recommends approximately 35% protein, 35% carbohydrates, and 30% fat. For muscle gain: 28% protein, 48% carbohydrates, and 24% fat. For maintenance: 25% protein, 50% carbohydrates, and 25% fat. Use our Macro Calculator for even more granular macro targets customised to your body weight. If you follow a ketogenic diet, our Keto Macro Calculator provides ketosis-specific targets.
Average Daily Calorie Needs by Age and Activity Level
| Age Group | Women -- Moderate Activity | Men -- Moderate Activity |
|---|---|---|
| 19-25 years | 2,000-2,200 kcal | 2,600-2,800 kcal |
| 26-35 years | 1,900-2,100 kcal | 2,400-2,600 kcal |
| 36-50 years | 1,800-2,000 kcal | 2,200-2,500 kcal |
| 51-65 years | 1,700-1,900 kcal | 2,100-2,400 kcal |
| 65+ years | 1,600-1,800 kcal | 2,000-2,200 kcal |
| Pregnant (2nd trim.) | +340 kcal above baseline | - |
| Breastfeeding | +500 kcal above baseline | - |
Tips for Hitting Your Daily Calorie Target
- Track for at least 2 weeks before changing anything: Most people significantly underestimate their calorie intake -- sometimes by 40-50%. Use a food diary app to understand your actual intake. Awareness alone often produces positive behaviour change.
- Prioritise protein at every meal: Protein is the most satiating macronutrient -- it reduces hunger hormones and increases satiety hormones more than carbs or fat. Building meals around a protein source naturally keeps calorie intake in check.
- Drink water before meals: Studies show that drinking 500ml of water 30 minutes before meals reduces calorie intake by approximately 13%. Adequate hydration is also essential for metabolism. Use our Water Intake Calculator for your daily target.
- Increase daily movement (NEAT): Non-exercise activity thermogenesis -- walking, standing, fidgeting -- can burn 200-400 extra calories daily without formal exercise. Use our Steps to Calories Calculator to understand how walking affects your daily burn.
- Recalculate every 5-10 kg: Your calorie needs change as your weight changes. Failing to recalculate is the most common reason weight loss plateaus after initial success.
- Prioritise sleep: Poor sleep increases ghrelin (hunger hormone) by 28% and decreases leptin (satiety hormone) by 18%, leading to 385 extra calories consumed per day on average. Sleep quality is nutrition quality. Use our Sleep Calculator to optimise your sleep cycles.
- Check your blood sugar regularly: Blood sugar fluctuations drive hunger and cravings. Monitor with our Blood Sugar Checker. If you have risk factors for diabetes, use our Diabetes Risk Calculator.
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