Calorie Calculator
Calculate your daily calorie needs for weight maintenance, loss, or gain. Uses the Mifflin-St Jeor equation — one of the most accurate formulas for estimating Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE).
What Are Calories?
A calorie is a unit of energy. In nutrition, calories refer to the energy people get from the food and drink they consume, and the energy they use in physical activity. When we talk about calories in food, we're actually referring to kilocalories (kcal). One kilocalorie equals 1,000 calories, which is the amount of energy needed to raise the temperature of 1 kilogram of water by 1°C.
Understanding your daily calorie needs is essential for:
- Weight Maintenance: Consuming the same number of calories you burn.
- Weight Loss: Creating a calorie deficit by eating fewer calories than you burn.
- Weight Gain: Creating a calorie surplus by eating more calories than you burn.
What Is BMR and TDEE?
Basal Metabolic Rate (BMR) is the number of calories your body needs to accomplish its most basic (basal) life-sustaining functions. This includes breathing, circulation, cell production, nutrient processing, protein synthesis, and ion transport. BMR accounts for about 60-70% of the total calories you burn each day.
Total Daily Energy Expenditure (TDEE) is the total number of calories you burn each day when exercise is taken into account. TDEE is calculated by multiplying your BMR by an activity factor that represents your daily activity level. Your TDEE represents the number of calories you need to consume daily to maintain your current weight.
How Does the Calorie Calculator Work?
This calculator uses the Mifflin-St Jeor equation, which is currently considered the most accurate BMR formula for adults.
For Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age(y) + 5
For Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age(y) − 161
In imperial units: weight in lbs × 4.536, height in inches × 15.88
TDEE is calculated by multiplying your BMR by an activity factor:
- Sedentary: BMR × 1.2 (little or no exercise)
- Lightly Active: BMR × 1.375 (1-3 days/week)
- Moderately Active: BMR × 1.55 (3-5 days/week)
- Very Active: BMR × 1.725 (6-7 days/week)
- Extra Active: BMR × 1.9 (athlete/physical job)
For weight loss or gain, the calculator adjusts your target by a 500-calorie deficit or surplus (default), which results in approximately 0.5 kg (1 lb) of weight change per week.
Why Use This Calorie Calculator?
- Accurate Formula: Uses the Mifflin-St Jeor equation, considered the most accurate for BMR estimation.
- Flexible Units: Switch between metric and imperial measurement systems.
- Goal-Oriented: Get personalized calorie targets for maintenance, loss, or gain.
- Macro Recommendations: Optional protein, carb, and fat guidelines.
- Free & Private: No registration, no data storage.
❓ Calorie Calculator FAQ
What is a calorie?
A calorie is a unit of energy. In nutrition, calories refer to the energy people get from the food and drink they consume, and the energy they use in physical activity. When we talk about calories in food, we're actually referring to kilocalories (kcal).
What is the difference between BMR and TDEE?
BMR (Basal Metabolic Rate) is the number of calories your body needs at rest to maintain basic functions like breathing and circulation. TDEE (Total Daily Energy Expenditure) is the total calories you burn each day, including physical activity. TDEE = BMR × Activity Factor.
How accurate is this calorie calculator?
This calculator uses the Mifflin-St Jeor equation, which is currently considered the most accurate for estimating BMR in healthy individuals. However, individual variations in metabolism, body composition, and health conditions can affect actual calorie needs. Use the results as a starting point and adjust based on your progress.
How many calories should I eat to lose weight?
To lose weight, you need to create a calorie deficit — eating fewer calories than you burn. A deficit of 500 calories per day typically results in about 0.5 kg (1 lb) of weight loss per week. The calculator shows a target for weight loss based on your TDEE.
How many calories should I eat to gain weight?
To gain weight, you need to create a calorie surplus — eating more calories than you burn. A surplus of 500 calories per day typically results in about 0.5 kg (1 lb) of weight gain per week. The calculator shows a target for weight gain based on your TDEE.
What is the Mifflin-St Jeor equation?
The Mifflin-St Jeor equation is a formula for calculating BMR. It was developed in 1990 and is considered more accurate than the older Harris-Benedict equation. For men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age(y) + 5. For women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age(y) − 161.
How does activity level affect my calorie needs?
Your activity level determines how many calories you burn beyond your BMR. The more active you are, the higher your TDEE and the more calories you need to maintain your weight. The calculator includes five activity levels from sedentary to extra active.
Should I eat back exercise calories?
If you're using a moderate activity level setting that accounts for your regular exercise, you shouldn't eat back additional calories from exercise. However, if you have an unusually intense workout day, you might need a small additional snack to fuel recovery.
Why am I not losing weight even though I'm eating fewer calories?
Several factors can affect weight loss: inaccurate calorie tracking, metabolic adaptation (your metabolism slows down during weight loss), water retention, changes in activity levels, or inaccurate estimation of your calorie needs. Consider consulting with a healthcare professional or dietitian for personalized advice.
Is it safe to eat less than 1200 calories per day?
For most adults, eating fewer than 1200 calories per day is not recommended without medical supervision. Such low-calorie diets can lead to nutrient deficiencies, muscle loss, and a slowed metabolism. Always aim for sustainable, healthy weight loss.
What are macronutrients?
Macronutrients are the nutrients your body needs in large amounts: protein, carbohydrates, and fat. Each provides calories: protein and carbohydrates provide 4 calories per gram, while fat provides 9 calories per gram. The calculator can show recommended daily targets for each.
How much protein do I need per day?
Protein needs vary based on activity level and goals. A general recommendation is 0.8 g per kg of body weight for sedentary individuals, 1.2-1.7 g per kg for active individuals, and 1.6-2.2 g per kg for those building muscle. The calculator uses 1.6 g per kg for active individuals.
How do I calculate my TDEE?
TDEE is calculated by multiplying your BMR by an activity factor. For example, if your BMR is 1500 calories and you're moderately active (factor 1.55), your TDEE is 1500 × 1.55 = 2325 calories per day. This calculator does this for you automatically.
How often should I recalculate my calorie needs?
Recalculate your calorie needs whenever your weight changes significantly (5+ kg or 10+ lbs), when your activity level changes substantially, or every 3-6 months as part of routine check-ins on your health and fitness goals.
What is the best diet for weight loss?
The best diet for weight loss is one that creates a sustainable calorie deficit while providing adequate nutrition. Focus on nutrient-dense foods like vegetables, fruits, lean proteins, and whole grains. Stay hydrated, practice portion control, and limit processed foods and sugary drinks.
How much exercise do I need for weight loss?
Aim for at least 150 minutes of moderate aerobic activity or 75 minutes of vigorous activity per week. Include strength training exercises at least 2 days per week. Incorporate more movement into your daily routine like walking and taking stairs.
Is this calculator suitable for athletes?
Yes, this calculator includes an "Extra Active" activity level (factor 1.9) for athletes and those with physically demanding jobs. However, athletes may need additional calories for performance and recovery beyond what the calculator estimates.
What is the difference between calories and kilocalories?
In nutrition, the terms "calorie" and "kilocalorie" are often used interchangeably. One kilocalorie (kcal) equals 1,000 calories. The "calories" listed on food labels are actually kilocalories. This calculator uses kcal, which is the standard in nutrition.