Calculators
Calorie Calculator
Calculate your daily calorie needs based on age, gender, height, weight, and activity level. Find out how many calories you need to maintain, lose, or gain weight with scientifically-backed formulas.
Use Calorie Calculator to get instant results without uploads or sign-ups. Everything runs securely in your browser for fast, reliable output.
Your results will appear here.
About this tool
Your daily calorie needs depend on multiple factors including your age, sex, weight, height, and physical activity level. Our Calorie Calculator uses the scientifically validated Mifflin-St Jeor equation, which is considered the most accurate predictor of resting energy expenditure. This calculator provides your Basal Metabolic Rate (BMR) - the calories you burn at rest - and your Total Daily Energy Expenditure (TDEE) - the total calories you burn including physical activity.
Understanding your calorie needs is crucial for achieving any body composition goal. To lose one pound of body weight, you need to create a calorie deficit of approximately 3,500 calories. Our calculator provides safe recommendations: a 500-calorie deficit for gradual weight loss (1 lb per week), maintenance calories for weight stability, or a 300-500 calorie surplus for healthy muscle gain. These recommendations help you avoid extreme dieting which can slow metabolism and cause muscle loss.
The calculator accounts for different activity levels from sedentary (little to no exercise) to extremely active (physical job or training twice daily). Being honest about your activity level is crucial for accuracy. The most common mistake is overestimating activity level, which leads to consuming too many calories. Physical activity multipliers range from 1.2 for sedentary individuals to 1.9 for extremely active people, showing how significantly exercise impacts your daily calorie needs.
All calculations are performed instantly in your browser with complete privacy. No personal health data is stored or transmitted to any server. The calculator works on any device and provides detailed breakdowns of your results, including recommended macronutrient ranges. Remember that these are estimates - individual metabolic rates can vary by 10-15% due to genetics, muscle mass, and other factors. Use these results as a starting point and adjust based on your actual progress.
Usage examples
Sedentary Office Worker Weight Loss
30-year-old female, 5'4", 160 lbs, sedentary, wants to lose weight
BMR: 1,450 calories/day. TDEE: 1,740 calories/day. For weight loss (1 lb/week): 1,240 calories/day. This creates a 500 calorie deficit. At this rate, she would lose approximately 4 pounds per month.
Active Male Muscle Gain
25-year-old male, 6'0", 175 lbs, exercises 4-5 times/week, wants to gain muscle
BMR: 1,820 calories/day. TDEE: 2,821 calories/day. For muscle gain: 3,121 calories/day. This 300-calorie surplus supports muscle growth while minimizing fat gain. Combined with resistance training, expect 0.5-1 lb of lean mass gain per week.
Moderately Active Maintenance
45-year-old male, 5'10", 185 lbs, exercises 3-4 times/week, wants to maintain
BMR: 1,755 calories/day. TDEE: 2,720 calories/day. For maintenance: 2,720 calories/day. This is the calorie intake that maintains current weight. No deficit or surplus needed.
Very Active Female Athlete
22-year-old female, 5'6", 135 lbs, trains 6-7 times/week (athlete)
BMR: 1,370 calories/day. TDEE: 2,329 calories/day. For maintenance during training: 2,329 calories/day. High activity level requires significantly more calories than sedentary individuals of the same size.
Older Adult Weight Loss
60-year-old male, 5'9", 200 lbs, light exercise 1-3 times/week
BMR: 1,640 calories/day. TDEE: 2,264 calories/day. For gradual weight loss: 1,764 calories/day. Slower metabolism due to age requires patience. A 500-calorie deficit is still effective but may feel more restrictive.
How to use
- Optional: Select a Quick Start preset (Weight Loss, Maintenance, Muscle Gain, or Extreme Cut)
- Select your biological sex (Male or Female) - affects base metabolic rate
- Enter your age in years - metabolism naturally slows with age
- Enter your current weight in pounds or kilograms
- Enter your height in feet/inches or centimeters
- Select your activity level from sedentary to extremely active
- Choose your goal: lose weight, maintain, or gain weight
- Click "Run Tool" to see your personalized calorie targets
- Review your BMR (Basal Metabolic Rate) and TDEE (Total Daily Energy Expenditure)
- Check your weight change timeline and macro recommendations
- Follow the recommended calorie intake to achieve your goals safely
- Each output has its own Copy button for easy tracking
Benefits
- Uses scientifically validated Mifflin-St Jeor equation (most accurate BMR formula)
- Calculates both BMR (resting metabolism) and TDEE (total daily needs)
- Personalized recommendations for weight loss, maintenance, or gain goals
- Accounts for 5 different activity levels from sedentary to very active
- Safe calorie deficit/surplus recommendations to prevent metabolic damage
- Works with both imperial (lbs, feet) and metric (kg, cm) units
- Instant calculations with detailed explanations of results
- No registration, login, or personal data collection required
- Complete privacy - all calculations performed in your browser
- Mobile-friendly interface works on any device
- Free forever with no hidden fees or premium upsells
- Helps prevent common diet mistakes like extreme calorie restriction
FAQs
What is a safe calorie deficit for weight loss?
A safe calorie deficit is typically 500-750 calories per day below your TDEE, resulting in 1-1.5 pounds of weight loss per week. This moderate approach preserves muscle mass, maintains energy levels, and prevents metabolic adaptation. Never create a deficit larger than 1000 calories/day without medical supervision. Women should not eat below 1,200 calories/day and men should stay above 1,500 calories/day, as going below these minimums can cause nutrient deficiencies, muscle loss, hormonal disruption, and metabolic slowdown that makes long-term weight loss harder.
What is BMR and TDEE?
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest to maintain basic life functions like breathing, circulation, and cell production. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor - it represents the total calories you burn in a day including all physical activity. For example, if your BMR is 1,500 and you're moderately active (1.55x multiplier), your TDEE would be 2,325 calories.
Which calorie formula is most accurate?
Our calculator uses the Mifflin-St Jeor equation, which research shows is the most accurate predictor of resting energy expenditure in healthy adults. It's more accurate than the older Harris-Benedict equation because it was developed using modern data. The Mifflin-St Jeor equation has an accuracy rate of about 10%, meaning your actual BMR is typically within 10% of the calculated value. Other factors like muscle mass, genetics, and metabolic adaptations can cause individual variation.
How many calories should I eat to lose weight?
For safe, sustainable weight loss, create a calorie deficit of 500 calories per day below your TDEE. This results in losing approximately 1 pound per week (3,500 calorie deficit = 1 pound). Never eat below 1,200 calories/day (women) or 1,500 calories/day (men) without medical supervision, as this can slow metabolism, cause muscle loss, and lead to nutrient deficiencies. Aggressive deficits above 1,000 calories/day are not recommended except under medical care.
Why does sex/gender affect calorie needs?
Males typically require more calories than females of the same age, weight, and height because they naturally have more muscle mass and less body fat percentage. Muscle tissue burns more calories at rest than fat tissue. The Mifflin-St Jeor equation accounts for this difference: males have a base calculation of 10 × weight (kg) + 6.25 × height (cm) - 5 × age + 5, while females use -161 instead of +5, reflecting the natural metabolic difference.
Should I eat back calories burned during exercise?
If you selected an activity level that includes your regular exercise, you don't need to eat back exercise calories - they're already factored into your TDEE. However, if you selected "sedentary" and then do occasional workouts, you may want to eat back 50-75% of estimated exercise calories (not 100%, as calorie burn estimates are often inflated). For example, if you burn 400 calories in a workout, eating an extra 200-300 calories that day helps prevent excessive fatigue while maintaining your deficit.
How often should I recalculate my calorie needs?
Recalculate every 10-15 pounds of weight change, or whenever your activity level significantly changes. As you lose weight, your BMR decreases because you have less body mass to maintain. For example, a person who loses 30 pounds might need 200-300 fewer calories than when they started. This is normal adaptation, not "damaged metabolism." Conversely, gaining muscle mass through resistance training can increase your BMR slightly.
Why am I not losing weight at my calculated deficit?
Several factors can affect results: (1) You may be overestimating your activity level - most people are less active than they think. (2) Food tracking inaccuracies - studies show people underestimate intake by 20-40%. (3) Water retention from new exercise, high sodium, or hormonal changes can mask fat loss for 2-4 weeks. (4) The 10-15% individual variation in metabolism. If you're truly eating at a deficit for 4+ weeks with no change, reduce calories by another 100-200 per day or increase activity. Patience is crucial - aim for 0.5-1% body weight loss per week.
Is it safe to eat significantly below my BMR?
No, eating significantly below your BMR (the calories needed just to sustain basic body functions) is not recommended and can be dangerous. Extreme calorie restriction causes metabolic slowdown, muscle loss, hormonal disruptions, decreased immune function, and increased hunger signals. Your body adapts by reducing energy expenditure and increasing hunger hormones, making long-term weight loss harder. Always eat at least your BMR, and preferably only 500 calories below your TDEE for safe, sustainable results.
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