Wondering how many calories your body needs each day? Our calorie calculator gives you science-based answers fast.

Using proven formulas like the Mifflin-St Jeor and Harris-Benedict equations, it helps you understand your ideal calorie intake—whether you’re aiming to lose weight, gain muscle, or maintain a healthy balance.

Built for real life and tailored to your age, gender, and activity level, it’s perfect for diet planning, fitness, and sustainable health.

How the Calorie Calculator Works

First, the calculator determines your Basal Metabolic Rate (BMR)—the number of calories your body burns at rest. Then, it multiplies that number by your activity level to get your Total Daily Energy Expenditure (TDEE).

The formulas used are:

• Mifflin-St Jeor (Primary): BMR = 10×weight (kg) + 6.25×height (cm) – 5×age (yrs) + 5 (men) or −161 (women)
• TDEE = BMR × Activity Multiplier
• Katch-McArdle: (Optional) Uses lean body mass for highly active users or athletes

This gives a reliable estimate of how many calories per day your body uses based on energy expenditure.

How to Use This Calculator

1. Enter your age, gender, weight, and height
2. Select your activity level (from sedentary to very active)
3. Choose your preferred unit (metric or imperial)
4. Click “Calculate”
5. Get your results: maintenance, weight loss, and weight gain targets

Whether you’re working toward a healthy weight or refining your eating patterns, this tool adapts to your goals.

How Many Calories Should You Eat?

Once you know your TDEE, apply these general calorie guidelines:

• Maintenance: Eat your TDEE amount
• Weight Loss: TDEE − 500 to 1000 kcal per day = 0.5 to 1 pound a week
• Weight Gain: TDEE + 250 to 500 kcal per day
• Minimums: Don’t drop below 1,200 kcal (women) or 1,500 kcal (men) unless supervised

These targets help avoid nutritional deficiencies while promoting long-term results.

Zigzag Calorie Cycling

Zigzag calorie cycling rotates high and low-calorie days to prevent metabolic slowdown and plateaus.

Example Weekly Plan:

• Mon/Wed/Fri: 2,200 kcal
• Tue/Thu/Sat/Sun: 1,600 kcal

This approach maintains your average caloric goal across the week but supports better eating patterns, energy levels, and fat-burning metabolism.

Calories and Nutrition: Not All Calories Are Equal

Calories matter, but so does the quality of your food. Focus on:

• Protein: Helps preserve lean mass and reduce hunger
• Fiber: Regulates digestion and blood sugar
• Healthy fats: Support hormones and heart health
• Whole foods: Nutrient-dense and less processed

Empty calories from sugar or fried foods offer little value and may impact how your body burns energy.

Real-Life Example

User Profile: Male, 28 years old, 75 kg, 175 cm, moderate activity

BMR: 10×75 + 6.25×175 – 5×28 + 5 = 1,729 kcal

TDEE: BMR × 1.55 = 1,729 × 1.55 ≈ 2,680 kcal/day

Weight Loss Target: 2,680 – 500 = 2,180 kcal/day

This example shows how age, weight, height, and physical activity determine energy needs.

FAQ

Q1: How accurate is the calorie calculator?

A: It provides an estimate based on established formulas. For clinical precision, consult a dietitian or metabolic lab.

Q2: Can I use it to gain muscle?

A: Yes. Add 250–500 kcal to your TDEE and prioritize protein and resistance training for lean muscle gain.

Q3: What happens if I eat too few calories?

A: You may lose muscle, reduce metabolism, and increase nutrient risk. Never drop below safe intake thresholds.

Q4: Should I count calories burned from exercise?

A: Yes, especially if your goal is weight balance. Adjust TDEE to reflect higher heart rate days.

Q5: Can I lose weight without exercise?

A: Yes, through diet alone. But combining diet with movement supports faster, safer weight loss and better body composition.

Reviewed by a Registered Dietitian

Written by: Dr. Hannah Lee, MSc, RD
Clinical Nutrition Specialist | 10+ years in weight loss & metabolic health

Disclaimer: This tool is informational and does not replace medical advice. Consult a licensed provider for personal health plans.

🎯 Ready to Reach Your Health Goals?

Use our Calorie Calculator now and take control of your nutrition. Whether your goal is losing weight, building muscle, or staying healthy, the first step is knowing your numbers.

References

• Mifflin et al. (1990) – Predictive Equation for Resting Energy Expenditure
• Frankenfield et al. (2005) – Systematic Review of RMR Equations
• Katch & McArdle – Nutrition, Weight Control, and Exercise
• Dietary Guidelines for Americans 2020–2025 – NIH
• Weinheimer et al. (2010) – Effects of Diet & Exercise on Fat-Free Mass
• Trexler et al. (2014) – Metabolic Adaptation to Weight Loss
• Hall & Kahan (2018) – Long-Term Obesity Management
• Calories and Weight Loss – Harvard T.H. Chan School of Public Health

All calculations and recommendations are for informational use only. Consult a licensed professional for personalized dietary planning.