MyFitnessPal Weight Loss Calculator
Calculate your daily calorie needs and projected weight loss timeline accurately.
Calorie & Weight Loss Planner
Configure your current stats and goals below.
Female
Male
Please enter a valid age (10-100).
Feet and Inches
Enter a valid positive weight.
Goal weight must be realistic.
Sedentary (Bank teller, desk job)
Lightly Active (Teacher, walking slightly)
Moderately Active (Server, construction)
Very Active (Athlete, daily hard exercise)
Extra Active (Training 2x/day)
Be honest! Most people overestimate activity.
Lose 0.5 lbs/week (Sustainable)
Lose 1 lb/week (Recommended)
Lose 1.5 lbs/week (Aggressive)
Lose 2 lbs/week (Very Aggressive)
Maintain Weight
Daily Calorie Target
1,850 kcal
Based on TDEE minus deficit
Estimated Time
30 Weeks
Projected Date
–
TDEE (Maintenance)
2,350
Macronutrient Breakdown (Standard 50/30/20)
| Nutrient | Percentage | Calories | Grams |
|---|
Weight Loss Projection
Projected Weight
Goal Weight
Article Contents
What is the MyFitnessPal Weight Loss Calculator?
The MyFitnessPal weight loss calculator is a digital tool designed to help individuals determine the precise daily caloric intake required to reach a specific body weight goal. Unlike generic health calculators, this tool mimics the robust logic used by the popular MyFitnessPal application, focusing on the principle of Energy Balance or "Calories In, Calories Out" (CICO).
This calculator is essential for anyone looking to lose fat, gain muscle, or maintain their current physique. It works by estimating your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) to create a personalized nutrition plan. Whether you are an office worker with a sedentary lifestyle or an athlete, understanding these numbers is the first step toward controlled, sustainable weight management.
Who should use this? It is ideal for dieters, athletes, and anyone medically advised to manage their weight. However, it is important to note a common misconception: calculators provide estimates, not absolute laws. Individual metabolism varies, and these figures serve as a highly accurate starting point for your journey.
The Mathematics of Weight Loss (Formulas)
The core of the MyFitnessPal weight loss calculator relies on the Mifflin-St Jeor Equation, widely considered the most accurate formula for estimating calorie needs in clinical settings. The process involves three distinct mathematical steps:
Step 1: Calculate BMR (Basal Metabolic Rate)
BMR is the energy your body needs just to survive at rest (breathing, circulation, cell production).
- Men: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
- Women: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
Step 2: Calculate TDEE (Total Daily Energy Expenditure)
To find how many calories you burn in a real day, we multiply BMR by an Activity Factor:
| Activity Level | Multiplier | Description |
|---|---|---|
| Sedentary | 1.2 | Little to no exercise, desk job |
| Lightly Active | 1.375 | Light exercise 1-3 days/week |
| Moderately Active | 1.55 | Moderate exercise 3-5 days/week |
| Very Active | 1.725 | Hard exercise 6-7 days/week |
Step 3: Apply the Deficit
To lose weight, you must consume fewer calories than your TDEE. The standard calculation used is:
1 lb of fat ≈ 3,500 calories.
Therefore, to lose 1 lb per week, you need a deficit of 500 calories per day (500 × 7 = 3,500).
Real-World Examples
Case Study 1: The Office Worker
Profile: John, 40 years old, 5'10", 200 lbs, works in accounting (Sedentary).
Goal: Reach 180 lbs by losing 1 lb/week.
- BMR Calculation: ~1,850 calories
- TDEE (Maintenance): 1,850 × 1.2 = 2,220 calories
- Deficit Required: 500 calories/day
- Daily Target: 2,220 – 500 = 1,720 calories
Financial/Time Investment: At this rate, John will reach his goal in approximately 20 weeks.
Case Study 2: The Active Teacher
Profile: Sarah, 29 years old, 165 cm, 70 kg, teaches elementary school and walks often (Lightly Active).
Goal: Reach 65 kg by losing 0.5 kg (~1.1 lbs) per week.
- BMR Calculation: ~1,450 calories
- TDEE (Maintenance): 1,450 × 1.375 = 1,993 calories
- Deficit Required: 550 calories/day (for 0.5kg loss)
- Daily Target: 1,993 – 550 = 1,443 calories
How to Use This MyFitnessPal Weight Loss Calculator
- Select Your Units: Choose between Imperial (lbs/ft) or Metric (kg/cm) depending on your preference.
- Input Physical Stats: Enter your age, gender, height, and current weight accurately.
- Set Activity Level: Be honest here. Underestimating activity is better than overestimating if you want faster results.
- Choose Your Pace: Select how much weight you want to lose per week. We recommend 1 lb (0.45 kg) as a sustainable "Goldilocks" zone.
- Analyze Results: Review your "Daily Calorie Target." This is the number you should aim for in your food tracking app.
- Check Macros: Look at the table to see how much Protein, Carbohydrates, and Fats you should consume.
Key Factors That Affect Weight Loss Results
While the MyFitnessPal weight loss calculator provides a mathematical ideal, several real-world factors influence your actual progress:
1. Metabolic Adaptation
As you lose weight, your body requires less energy to move. A lighter body burns fewer calories. You may need to recalculate your numbers every 10 lbs lost.
2. TEF (Thermic Effect of Food)
Not all calories are equal. Protein requires more energy to digest than fats or carbs. A high-protein diet can effectively increase your daily expenditure by 50-100 calories.
3. Non-Exercise Activity Thermogenesis (NEAT)
This refers to fidgeting, standing, and walking. NEAT can vary by up to 800 calories between individuals, drastically affecting TDEE.
4. Water Weight Fluctuations
High sodium intake or hormonal cycles can cause water retention, masking fat loss on the scale. Do not panic if the scale doesn't move linearly every day.
5. Tracking Accuracy
Studies show people underestimate calorie intake by 30-50%. Using a food scale and precise logging is critical for the calculator to work.
6. Sleep and Stress
High cortisol (stress hormone) and lack of sleep can inhibit fat loss and increase cravings, making it harder to stick to the calculated deficit.
Frequently Asked Questions (FAQ)
1. Is the calorie count from this calculator 100% accurate?
No calculator is 100% perfect because every human body is unique. Consider this result a starting estimate. If you aren't losing weight after 2 weeks, lower the calories by another 100-200.
2. What is the lowest calorie amount I should eat?
Generally, medical professionals advise against dropping below 1,200 calories for women and 1,500 for men without supervision, to ensure nutrient sufficiency.
3. Should I eat back my exercise calories?
MyFitnessPal often adds exercise calories back. However, fitness trackers often overestimate burn. A safe approach is to eat back only 50% of what your watch says you burned.
4. Can I lose 5 lbs in one week?
While possible, it is mostly water weight and not recommended. Rapid weight loss often leads to muscle loss and metabolic slowdown.
5. How do I track macros?
Use the percentages provided in the results section (50% Carbs, 30% Fat, 20% Protein) as a guide when logging food in your app.
6. Why has my weight loss stalled?
This is called a plateau. It usually happens because you have lost weight, and your new BMR is lower. Recalculate your numbers using your new weight.
7. Does muscle weigh more than fat?
A pound is a pound. However, muscle is much denser than fat. You might lose inches without losing weight if you are building muscle while burning fat (recomposition).
8. Is a high-protein diet better?
For weight loss, yes. Protein keeps you full longer and helps preserve muscle mass while in a calorie deficit.
Related Tools and Internal Resources
- Calorie Deficit Calculator – A dedicated tool for finding your deficit sweet spot.
- BMR Calculator – Calculate your Basal Metabolic Rate without activity factors.
- TDEE Calculator – Find your Total Daily Energy Expenditure for maintenance.
- Macro Calculator – detailed breakdown of protein, fats, and carbs.
- BMI Chart & Calculator – Check your Body Mass Index status.
- Advanced Weight Loss Planner – Long-term planning for health goals.