Estimate your daily calorie needs based on your activity level, age, and fitness goals. This tool helps athletes, dietitians, and health-conscious individuals plan nutrition and training routines. Get personalized calorie targets for maintenance, weight loss, or muscle gain.
Calorie Calculator
Your Calorie Breakdown
How to Use This Tool
Follow these simple steps to get your personalized calorie estimates:
- Enter your age (must be between 15 and 100 years).
- Select your gender from the dropdown menu.
- Input your height using either centimeters or feet & inches, toggling the unit selector as needed.
- Enter your weight in kilograms or pounds, using the unit selector to switch between units.
- Choose your weekly activity level from sedentary to extra active.
- Select your fitness goal: maintain weight, lose 0.5kg/1kg per week, or gain 0.5kg/1kg per week.
- Click the Calculate Calories button to view your detailed breakdown.
- Use the Reset button to clear all inputs and start over, or Copy Results to save your estimates.
Formula and Logic
This calculator uses the Mifflin-St Jeor equation, the most widely accepted formula for estimating basal metabolic rate (BMR) for healthy adults. BMR represents the number of calories your body burns at rest to maintain basic physiological functions.
For male users: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age) + 5
For female users: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age) - 161
For users selecting "Other" gender, the calculator averages the male and female BMR values to provide a neutral estimate.
Total Daily Energy Expenditure (TDEE) is calculated by multiplying BMR by an activity level multiplier:
- Sedentary: BMR × 1.2
- Lightly Active: BMR × 1.375
- Moderately Active: BMR × 1.55
- Very Active: BMR × 1.725
- Extra Active: BMR × 1.9
Target calories are adjusted from TDEE based on your selected goal: a 550 kcal/day adjustment for 0.5kg weekly weight change, and 1100 kcal/day for 1kg weekly change. Targets are never set below your BMR to avoid unsafe calorie restriction.
Practical Notes
Calorie estimates are generalized and may vary based on individual factors not accounted for in this tool, including muscle mass, metabolic health, medication use, and hormonal conditions. Always consult a licensed dietitian or healthcare provider before starting a new nutrition or fitness plan, especially if you have underlying health conditions.
Weight loss or gain rates may differ from estimates: 1kg of body fat contains approximately 7700 kcal, but individual metabolism, water retention, and muscle gain/loss can affect scale weight. Aim for sustainable, gradual changes rather than extreme calorie restriction.
Athletes and highly active individuals should adjust calorie intake based on training periodization: increase calories during heavy training blocks, and reduce slightly during recovery phases. Pair calorie targets with adequate protein intake (1.6-2.2g per kg of body weight) to support muscle maintenance or growth.
Dietary guidelines recommend that adults get 45-65% of calories from carbohydrates, 20-35% from fats, and 10-35% from protein. Use your target calorie number to plan balanced meals that meet these macro ranges.
Why This Tool Is Useful
Generic calorie recommendations often fail to account for individual differences in age, gender, activity level, and goals. This tool provides personalized, actionable estimates that fitness enthusiasts, athletes, and dietitians can use to plan nutrition, adjust training loads, and track progress toward health goals.
Unlike simplified calculators that only provide a single TDEE number, this tool breaks down BMR, TDEE, and goal-adjusted targets, giving you a full picture of your energy needs. The copy function lets you easily save results to share with trainers or dietitians.
Frequently Asked Questions
Is the Mifflin-St Jeor formula accurate for everyone?
No, the formula provides an estimate for healthy adults and may be less accurate for elderly individuals, pregnant people, or those with metabolic disorders. It also does not account for high muscle mass, which can increase BMR beyond formula estimates.
Can I use this calculator if I am trying to build muscle?
Yes, select the "Gain 0.5kg" or "Gain 1kg" weekly goal to get a calorie surplus target. Pair this with resistance training and adequate protein intake to ensure weight gain comes from muscle rather than excess fat.
Why was my target calorie adjusted to my BMR?
The tool automatically caps deficits to avoid setting target calories below your BMR, which is the minimum number of calories your body needs to function at rest. Extremely low calorie intake can lead to nutrient deficiencies, muscle loss, and slowed metabolism.
Additional Guidance
Track your calorie intake and weight for 2-3 weeks to see if estimates align with your actual progress. If you are not seeing expected changes, adjust your intake by 100-200 kcal/day and reassess. Remember that hydration, sleep, and stress levels also impact weight and energy levels, so pair calorie planning with overall wellness habits.
Individuals with a history of eating disorders should avoid rigid calorie tracking and consult a healthcare provider before using this tool. This calculator is for informational purposes only and does not constitute medical or nutritional advice.