Estimate your ideal body weight using scientific principles.
Calculate Your Goal Weight
Enter your current weight in kilograms (kg).
Enter your height in centimeters (cm).
Enter your age in years.
Male
Female
Select your biological sex for more accurate calculations.
Sedentary (little to no exercise)
Lightly Active (exercise 1-3 days/week)
Moderately Active (exercise 3-5 days/week)
Very Active (exercise 6-7 days/week)
Extra Active (very intense exercise daily)
Choose the option that best describes your lifestyle.
Your Estimated Final Body Weight
—
Calculated using a modified Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) approach, adjusted for age, sex, and activity level to estimate a healthy target weight range.
BMR: — kcal/day
TDEE: — kcal/day
Healthy Weight Range: — to — kg
Projected Weight Trend
Visualizing potential weight changes based on activity level and a hypothetical daily calorie deficit/surplus.
Recommended Calorie Intake for Goal Weight
Target (kg)
BMR (kcal/day)
TDEE (Maintenance) (kcal/day)
Goal Intake (Loss) (kcal/day)
Goal Intake (Gain) (kcal/day)
What is Final Body Weight?
The concept of final body weight, often referred to as target body weight or ideal body weight, is a calculated estimate of a healthy weight range for an individual. It's not a single magic number but rather a spectrum of weights that are generally associated with lower health risks and better overall well-being, considering specific physiological factors. This calculation is crucial for individuals aiming to lose weight, gain weight, or simply maintain a healthy physique.
Who should use it? Anyone concerned about their current weight in relation to their health, individuals starting a weight management program, athletes looking to optimize performance, or even those undergoing medical assessments would benefit from understanding their estimated final body weight. It provides a quantitative benchmark for personal health goals.
Common misconceptions include believing that there's one universally perfect weight for everyone of a certain height, or that hitting a specific number on the scale is the sole indicator of health. Factors like body composition (muscle vs. fat), bone density, and overall fitness play significant roles that simple weight calculations don't fully capture. This final body weight calculator aims to provide a scientifically grounded estimate, but it should always be considered alongside professional medical advice and individual health status.
Final Body Weight Formula and Mathematical Explanation
Calculating a target final body weight involves estimating an individual's energy expenditure and then determining a caloric intake that would lead to a desired state. A common approach uses the Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE).
The Harris-Benedict equation (or Mifflin-St Jeor, often considered more accurate) is frequently used to estimate BMR. We will use the Mifflin-St Jeor equation here for its widespread acceptance:
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
Next, TDEE is calculated by multiplying the BMR by an activity factor:
TDEE = BMR × Activity Factor
The final body weight is then inferred by finding a weight where the TDEE supports a healthy lifestyle, or by projecting weight changes based on caloric adjustments from the current TDEE. A common simplification is to target a weight that corresponds to a healthy BMI range (e.g., 18.5-24.9), or to adjust calories to achieve a sustainable rate of weight change (e.g., 0.5-1 kg per week, which requires a deficit/surplus of approximately 500-1000 kcal/day).
Our calculator uses your current metrics (weight, height, age, sex) and activity level to first estimate your current BMR and TDEE. It then provides a healthy weight range (based on BMI) and suggests calorie targets for weight loss or gain relative to your current TDEE. The "Final Body Weight" displayed is an average target within this healthy BMI range.
Variables Used:
Variable
Meaning
Unit
Typical Range
Current Weight
Your current body mass.
kg
1 – 500+
Height
Your vertical stature.
cm
50 – 250+
Age
Your age in years.
Years
1 – 120
Gender
Biological sex influences metabolic rate.
Categorical
Male, Female
Activity Factor
Multiplier based on daily physical activity.
Decimal
1.2 (Sedentary) to 1.9 (Extra Active)
BMR
Basal Metabolic Rate: calories burned at rest.
kcal/day
Varies widely based on inputs
TDEE
Total Daily Energy Expenditure: calories burned including activity.
kcal/day
Varies widely based on inputs
Final Body Weight
Estimated target healthy weight.
kg
Varies widely based on inputs
Practical Examples (Real-World Use Cases)
Example 1: Weight Loss Goal
Scenario: Sarah is a 35-year-old female, 170 cm tall, weighing 80 kg. She works a desk job (Sedentary activity level) but wants to reach a healthier weight. She aims for a weight around 65 kg.
Inputs:
Current Weight: 80 kg
Height: 170 cm
Age: 35 years
Gender: Female
Activity Level: Sedentary (1.2)
Calculated Outputs (approximate):
BMR: ~1450 kcal/day
TDEE: ~1740 kcal/day
Healthy Weight Range (BMI 18.5-24.9): ~53.5 kg to ~71.8 kg
Estimated Final Body Weight: ~62.6 kg
Goal Intake for Weight Loss (0.5 kg/week): ~1240 kcal/day
Interpretation: Sarah's current weight is above the healthy range. Her estimated final body weight target is around 62.6 kg. To lose approximately 0.5 kg per week, she should aim for a daily intake of about 1240 kcal, maintaining her sedentary lifestyle. This calculation helps her set a realistic calorie goal for sustainable weight loss.
Example 2: Healthy Weight Maintenance
Scenario: John is a 45-year-old male, 180 cm tall, weighing 75 kg. He exercises moderately 3-5 times a week and wants to maintain his current healthy weight.
Inputs:
Current Weight: 75 kg
Height: 180 cm
Age: 45 years
Gender: Male
Activity Level: Moderately Active (1.55)
Calculated Outputs (approximate):
BMR: ~1700 kcal/day
TDEE: ~2635 kcal/day
Healthy Weight Range (BMI 18.5-24.9): ~60.1 kg to ~80.7 kg
Estimated Final Body Weight: ~70.4 kg
Goal Intake for Maintenance: ~2635 kcal/day
Interpretation: John's current weight of 75 kg falls within the healthy BMI range. His estimated final body weight target is around 70.4 kg. To maintain his current weight, he needs to consume approximately 2635 kcal per day, aligning with his moderately active lifestyle. This confirms his current intake is appropriate for maintenance if it's around this figure.
How to Use This Final Body Weight Calculator
Our final body weight calculator is designed for simplicity and accuracy. Follow these steps to get your personalized results:
Enter Current Weight: Input your current body mass in kilograms (kg).
Enter Height: Input your height in centimeters (cm).
Enter Age: Provide your age in years.
Select Biological Sex: Choose 'Male' or 'Female'.
Choose Activity Level: Select the option that best reflects your average daily physical activity.
Click 'Calculate Weight': The calculator will instantly process your inputs.
How to read results:
Estimated Final Body Weight: This is the central figure, representing an average healthy weight target based on your inputs.
BMR: Your Basal Metabolic Rate, the calories your body burns at complete rest.
TDEE: Your Total Daily Energy Expenditure, the total calories you burn daily, including physical activity. This is your maintenance calorie level.
Healthy Weight Range: A weight spectrum (based on a healthy BMI of 18.5-24.9) within which your weight is generally considered optimal for health.
Recommended Calorie Intake: The table provides estimated daily calorie targets for weight loss (at least 500 kcal deficit from TDEE for ~0.5 kg/week loss) and weight gain (at least 500 kcal surplus from TDEE for ~0.5 kg/week gain), as well as for maintenance.
Decision-making guidance: Use the calculated healthy weight range and target weight as a guide. If your current weight is outside this range, aim for the lower or upper end depending on your personal goals and body composition. Use the suggested calorie intakes to structure your diet for weight loss, gain, or maintenance. Always consult a healthcare professional before making significant changes to your diet or exercise routine.
Key Factors That Affect Final Body Weight Results
While our final body weight calculator provides a robust estimate, several real-world factors can influence the actual outcome and the precision of the calculation:
Body Composition: Muscle is denser than fat. Two individuals of the same height and weight can have vastly different health statuses based on their muscle-to-fat ratio. The calculator assumes a standard body composition for the calculations. A very muscular individual might weigh more but be healthier than someone with less muscle and more fat at a lower weight.
Genetics: Individual genetic makeup plays a role in metabolism, appetite regulation, and fat storage. Some people naturally have a higher or lower metabolic rate, which can affect how easily they gain or lose weight, making a standardized calculation an approximation.
Hormonal Factors: Conditions like thyroid issues (hypothyroidism or hyperthyroidism), PCOS, or hormonal changes during menopause can significantly impact metabolism and body weight, potentially skewing calculator results.
Metabolic Adaptations: When you lose weight, especially rapidly, your metabolism can slow down (metabolic adaptation). This means your TDEE decreases, and you might need to adjust calorie intake further to continue losing weight. The calculator's TDEE is an estimate for your current state.
Medications: Certain medications, such as steroids, some antidepressants, and diabetes medications, can cause weight gain or affect metabolism, influencing the effectiveness of calorie-based weight management strategies.
Dietary Quality vs. Quantity: The calculator focuses on calorie intake (quantity). However, the quality of food matters immensely. Nutrient-dense foods promote satiety and provide essential vitamins and minerals, while highly processed foods can lead to overconsumption and poor health outcomes, even within a calorie target.
Hydration and Sleep: Proper hydration and adequate sleep are critical for metabolic function and hormone regulation. Dehydration can be mistaken for hunger, and lack of sleep disrupts hormones that control appetite (ghrelin and leptin), potentially impacting weight management efforts.
Underlying Health Conditions: Chronic illnesses, digestive issues, and even minor health concerns can affect appetite, nutrient absorption, and energy levels, all of which influence weight and the body's response to dietary changes.
Frequently Asked Questions (FAQ)
What is the most accurate formula for calculating ideal body weight?
While the Mifflin-St Jeor equation used here is widely considered more accurate than the original Harris-Benedict equation for estimating BMR, no single formula is perfect for everyone. Body composition, genetics, and individual metabolic rates vary greatly. Using a calculator like this provides a good starting point, but consulting a healthcare professional for a personalized assessment is recommended.
Can I use this calculator if I'm pregnant or breastfeeding?
No, this calculator is not suitable for pregnant or breastfeeding individuals. Calorie and nutrient needs change dramatically during these periods. Consult with a doctor or a registered dietitian for appropriate guidance.
Does 'Biological Sex' matter for weight calculation?
Yes, biological sex significantly impacts BMR calculations due to differences in typical body composition (muscle mass vs. fat mass) and hormonal profiles. The formulas used account for these standard physiological differences.
What does a 'Sedentary' activity level mean?
A sedentary lifestyle typically involves minimal physical activity, such as sitting or standing for most of the day, with very light exercise or infrequent short walks. Office jobs often fall into this category.
How quickly should I aim to lose weight?
A safe and sustainable rate of weight loss is generally considered to be 0.5 to 1 kg (1 to 2 lbs) per week. This typically requires a daily calorie deficit of 500 to 1000 calories. Rapid weight loss can lead to muscle loss, nutrient deficiencies, and is often unsustainable long-term.
What if my current weight is very different from the healthy range?
If your current weight is significantly outside the healthy range, it's crucial to consult a healthcare provider. They can help you create a safe and effective plan tailored to your specific needs, considering any underlying health issues.
How does muscle mass affect my final body weight calculation?
Muscle is denser and metabolically more active than fat. While our calculator uses weight, height, age, and sex, it doesn't directly measure body composition. A highly muscular individual might weigh more than the 'ideal' weight but be very healthy. Focus on body composition (fat percentage) and how you feel, in addition to the calculated weight range.
Can I use this calculator for children?
This calculator is designed for adults. Children and adolescents have different growth and developmental needs, and their weight goals should be assessed by a pediatrician or healthcare professional.