TDEE and Weight Loss Calculator
Estimate your Total Daily Energy Expenditure and your weight loss journey.
TDEE & Weight Loss Calculator
Your Results
Estimated daily calorie intake for weight loss: — kcal
How it Works
We first calculate your Basal Metabolic Rate (BMR) using the Mifflin-St Jeor equation, which estimates the calories your body burns at rest. Then, we multiply your BMR by an activity factor to determine your Total Daily Energy Expenditure (TDEE). For weight loss, we establish a daily calorie target by creating a deficit from your TDEE, considering your weekly goal. Finally, we estimate the time needed to reach your goal weight based on this deficit.
Female: (10 * weight_kg) + (6.25 * height_cm) – (5 * age) – 161
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| Weight | Current body weight | kg | 30 – 200+ |
| Height | Current height | cm | 100 – 220 |
| Age | Years since birth | Years | 1 – 100+ |
| Activity Level | Multiplier based on daily physical activity | Unitless | 1.2 – 1.9 |
| Weekly Goal | Desired weight loss per week | kg/week | 0.25 – 1.0 |
| BMR | Calories burned at rest | kcal | 1000 – 2500+ |
| TDEE | Total calories burned daily | kcal | 1500 – 3500+ |
| Target Calories | Recommended daily intake for weight loss | kcal | 1200 – 2500+ |
Understanding TDEE and Weight Loss: Your Essential Guide
Navigating the world of weight management can be complex, but understanding your body's energy needs is a fundamental step. This guide delves into the concept of Total Daily Energy Expenditure (TDEE) and how it directly impacts your weight loss journey. We'll equip you with the knowledge and tools, including our advanced TDEE and Weight Loss Calculator, to set realistic goals and achieve sustainable results.
What is a TDEE and Weight Loss Calculator?
A TDEE and Weight Loss Calculator is an online tool designed to estimate the total number of calories your body burns in a single day (TDEE) and then project how long it might take to reach a specific weight loss goal based on a calculated calorie deficit. It takes into account various personal factors to provide a personalized calorie target for shedding unwanted pounds.
Who should use it? Anyone looking to lose weight, gain weight, or maintain their current weight can benefit from understanding their TDEE. It's particularly useful for individuals starting a fitness or diet plan, those experiencing weight fluctuations, or anyone wanting to gain a deeper insight into their metabolism and energy balance.
Common Misconceptions:
- "Calories in vs. Calories out" is the only factor: While crucial, nutrient timing, hormonal responses, and food quality also play roles in weight management.
- TDEE is static: Your TDEE changes as your weight, activity level, and even muscle mass fluctuate.
- Aggressive calorie deficits are always best: Rapid weight loss can lead to muscle loss, nutrient deficiencies, and is often unsustainable. A moderate, consistent deficit is generally more effective long-term.
- All calories are equal: While metabolically similar, the satiety and nutritional value of different foods vary significantly.
TDEE and Weight Loss Calculator Formula and Mathematical Explanation
The calculation involves several steps, often starting with estimating Basal Metabolic Rate (BMR) and then applying an activity factor to determine TDEE. The weight loss aspect then subtracts a calculated deficit.
Step 1: Calculating Basal Metabolic Rate (BMR)
The most common formula used is the Mifflin-St Jeor equation, considered more accurate than older formulas like Harris-Benedict.
- For Men: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
- For Women: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
This formula estimates the calories your body needs to perform basic life-sustaining functions (breathing, circulation, cell production) at complete rest.
Step 2: Calculating Total Daily Energy Expenditure (TDEE)
TDEE is your BMR multiplied by an Activity Factor (AF) that represents your average daily activity level.
- Sedentary (little to no exercise): AF = 1.2
- Lightly active (light exercise/sports 1-3 days/week): AF = 1.375
- Moderately active (moderate exercise/sports 3-5 days/week): AF = 1.55
- Very active (hard exercise/sports 6-7 days/week): AF = 1.725
- Extra active (very hard exercise/sports & physical job or 2x training): AF = 1.9
TDEE = BMR × Activity Factor
This figure represents the total calories you burn daily, including your BMR and the calories burned through all physical activities.
Step 3: Calculating Weight Loss Target and Timeline
To lose weight, you need to consume fewer calories than your TDEE, creating a calorie deficit. A common understanding is that a deficit of approximately 3,500 calories results in the loss of one pound of fat (about 0.45 kg). Therefore, a deficit of roughly 7,700 calories is needed to lose 1 kg of fat.
Weekly Calorie Deficit = Weekly Goal (kg) × 7700 kcal/kg
Daily Calorie Target = TDEE – (Weekly Calorie Deficit / 7 days)
Estimated Time to Reach Goal = (Current Weight – Goal Weight) / Weekly Goal (kg/week)
Variables Table
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| Weight | Current body weight | kg | 30 – 200+ |
| Height | Current height | cm | 100 – 220 |
| Age | Years since birth | Years | 1 – 100+ |
| Gender | Biological sex, affects BMR calculation | Male/Female | N/A |
| Activity Level | Multiplier based on daily physical activity | Unitless | 1.2 – 1.9 |
| Goal Weight | Target body weight | kg | 30 – 200+ |
| Weekly Goal | Desired weight loss per week | kg/week | 0.25 – 1.0 |
| BMR | Calories burned at rest | kcal | 1000 – 2500+ |
| TDEE | Total calories burned daily | kcal | 1500 – 3500+ |
| Target Calories | Recommended daily intake for weight loss | kcal | 1200 – 2500+ |
| Weekly Calorie Deficit | Total deficit needed per week | kcal | 1925 – 7700 |
| Time to Goal | Estimated weeks to reach target | Weeks | Varies greatly |
Practical Examples (Real-World Use Cases)
Example 1: Moderate Weight Loss Goal
Scenario: Sarah is a 30-year-old female, weighing 75 kg and standing 165 cm tall. She works an office job and exercises moderately 3-4 times a week. She wants to lose 10 kg and aims for a sustainable loss of 0.5 kg per week.
Inputs:
- Gender: Female
- Age: 30 years
- Weight: 75 kg
- Height: 165 cm
- Activity Level: Moderately active (1.55)
- Goal Weight: 65 kg
- Weekly Goal: 0.5 kg/week
Calculations:
- BMR = (10 * 75) + (6.25 * 165) – (5 * 30) – 161 = 750 + 1031.25 – 150 – 161 = 1470.25 kcal
- TDEE = 1470.25 * 1.55 = 2278.89 kcal (approx. 2279 kcal)
- Weekly Calorie Deficit = 0.5 kg * 7700 kcal/kg = 3850 kcal
- Daily Calorie Target = 2279 – (3850 / 7) = 2279 – 550 = 1729 kcal (approx. 1730 kcal)
- Estimated Time to Goal = (75 kg – 65 kg) / 0.5 kg/week = 10 kg / 0.5 kg/week = 20 weeks
Interpretation: Sarah should aim to consume approximately 1730 calories per day to lose 0.5 kg per week. At this rate, it would take her about 20 weeks to reach her goal weight of 65 kg. This is a realistic and sustainable approach to weight loss.
Example 2: Maintaining Weight with Increased Activity
Scenario: Mark is a 40-year-old male, weighing 85 kg and standing 180 cm tall. He recently increased his activity level significantly by starting a new, intense workout routine 5-6 days a week. He wants to maintain his current weight but build some muscle.
Inputs:
- Gender: Male
- Age: 40 years
- Weight: 85 kg
- Height: 180 cm
- Activity Level: Very active (1.725)
- Goal Weight: 85 kg (maintaining)
- Weekly Goal: 0 kg/week (implied for maintenance)
Calculations:
- BMR = (10 * 85) + (6.25 * 180) – (5 * 40) + 5 = 850 + 1125 – 200 + 5 = 1780 kcal
- TDEE = 1780 * 1.725 = 3073.5 kcal (approx. 3074 kcal)
- Weekly Calorie Deficit = 0 kg * 7700 kcal/kg = 0 kcal
- Daily Calorie Target = 3074 – (0 / 7) = 3074 kcal (approx. 3075 kcal)
- Estimated Time to Goal = (85 kg – 85 kg) / 0 kg/week = N/A (already at goal)
Interpretation: To maintain his current weight with his new activity level, Mark should consume around 3075 calories per day. If his goal is to build muscle, he might consider a slight surplus (e.g., 250-500 kcal above TDEE) to support muscle growth while minimizing fat gain. Understanding his TDEE is crucial for balancing energy intake and expenditure effectively.
How to Use This TDEE and Weight Loss Calculator
Using our calculator is straightforward and designed to give you actionable insights quickly.
- Enter Your Details: Accurately input your gender, age, current weight (in kg), and height (in cm).
- Select Activity Level: Choose the option that best reflects your daily physical activity. Be honest with yourself for the most accurate results.
- Set Your Goal: Enter your desired goal weight (in kg) and select your preferred weekly weight loss rate (0.25 kg to 1 kg per week). A rate of 0.5 kg per week is generally recommended for sustainable fat loss.
- Calculate: Click the "Calculate" button.
How to Read Results:
- BMR: Your resting metabolic rate – the minimum calories your body needs to function.
- TDEE: Your total daily calorie burn, including activity. This is your maintenance calorie level.
- Target Calories: The daily calorie intake recommended to achieve your set weekly weight loss goal.
- Weekly Calorie Deficit: The total calorie shortfall you need to create each week.
- Estimated Time to Reach Goal: A projected timeframe to hit your target weight.
Decision-Making Guidance:
- For Weight Loss: Aim to consume calories at or slightly below your 'Target Calories' while staying above a safe minimum (generally not below 1200 kcal for women, 1500 kcal for men, without medical supervision).
- For Weight Maintenance: Consume calories close to your 'TDEE'.
- For Weight Gain (e.g., muscle): Consume calories above your 'TDEE' (a surplus).
- Adjustments: Remember that these are estimates. Monitor your progress and adjust your calorie intake or activity level as needed. If weight loss stalls, you might need to slightly decrease calories or increase activity. If you're losing too quickly or feel fatigued, you may need to increase calorie intake slightly.
Key Factors That Affect TDEE Results
While our calculator uses established formulas, several factors can influence your actual TDEE and weight loss progress:
- Metabolic Adaptation: As you lose weight, your BMR and TDEE naturally decrease because there's less body mass to maintain. Your body may also become more efficient, slightly lowering calorie burn. This is why plateaus happen.
- Body Composition: Muscle tissue burns more calories at rest than fat tissue. Individuals with higher muscle mass have a higher BMR and TDEE, even at the same weight.
- Hormonal Factors: Thyroid hormones, insulin, leptin, and others significantly regulate metabolism. Imbalances (like hypothyroidism) can drastically alter TDEE.
- Genetics: Your inherited genes play a role in your metabolic rate and how efficiently your body stores or burns fat.
- Thermic Effect of Food (TEF): Your body uses energy to digest, absorb, and metabolize food. Protein has a higher TEF than carbohydrates or fats, meaning it burns more calories during digestion.
- NEAT (Non-Exercise Activity Thermogenesis): This includes calories burned from fidgeting, walking around, maintaining posture, and other activities outside of structured exercise. NEAT can vary significantly between individuals and days.
- Sleep Quality and Stress: Poor sleep and high stress levels can negatively impact hormones like cortisol and ghrelin, potentially increasing appetite and slowing metabolism.
- Age: Metabolic rate tends to decrease slightly with age, primarily due to potential loss of muscle mass and hormonal changes.