Weight Loss Calculator
Plan your weight loss journey with this free calculator. Enter current weight, target weight, and activity to estimate weeks needed to reach your goal with charts and breakdowns.
About This Calculator
Our Weight Loss Calculator helps you create a personalized exercise-based weight loss plan. By entering your current weight, target weight, preferred physical activity, and exercise schedule, you can estimate how many weeks it will take to reach your goal with a healthy and sustainable approach.
The calculator uses the scientific Metabolic Equivalent of Task (MET) formula to estimate calories burned during exercise: Calories per minute = MET × 3.5 × weight (kg) / 200. Each kilogram of body fat equals approximately 7,700 calories. Based on your chosen weight loss pace (slow at 0.25 kg/week, moderate at 0.5 kg/week, or fast at 1.0 kg/week), the tool calculates your weekly calorie deficit target and shows how much of that deficit comes from exercise versus diet.
This calculator supports 18 different activities including running, walking, cycling, swimming, HIIT, yoga, weightlifting, and more, each with validated MET values from the 2011 Compendium of Physical Activities. The results include a breakdown of calories burned per session, weekly exercise calories, additional daily diet deficit needed, and an estimated timeline to reach your goal weight.
Regional Notes
India (IN): The ICMR recommends a daily calorie intake of 1,600-2,400 kcal depending on activity level. Weight loss of 0.5-1 kg per week is considered safe. Popular activities include brisk walking, yoga, and cricket.
United States (US): The US Dietary Guidelines recommend 1,600-2,400 kcal/day for women and 2,000-3,000 kcal/day for men. The CDC recommends 150-300 minutes of moderate-intensity exercise per week for weight management.
United Kingdom (UK): The NHS recommends 2,000 kcal/day for women and 2,500 kcal/day for men, with at least 150 minutes of moderate activity per week. The 7,700 kcal per kg conversion is used by the British Dietetic Association.
Frequently Asked Questions
How many calories equal 1 kg of body fat?
One kilogram of body fat is approximately equal to 7,700 calories. This means you need to create a calorie deficit of 7,700 calories through exercise and diet to lose 1 kg of body weight. This calculator uses this standard conversion factor to estimate your weight loss timeline.
What is a safe and sustainable weight loss pace?
A safe and sustainable weight loss pace is 0.5 to 1 kg (1 to 2 pounds) per week according to health authorities worldwide. Losing weight faster than this often results in muscle loss, nutritional deficiencies, and is difficult to maintain long-term. This calculator offers slow (0.25 kg/week), moderate (0.5 kg/week), and fast (1 kg/week) pace options.
How are calories burned during exercise calculated?
Calories burned are calculated using the Metabolic Equivalent of Task (MET) formula: Calories burned per minute = MET × 3.5 × weight in kg / 200. The MET value represents the energy cost of a specific activity compared to resting. For example, running has a MET of 9.8 while walking has a MET of 3.5, meaning running burns nearly three times more calories per minute than walking for the same person.
Can I lose weight through exercise alone?
While exercise is an important component of weight loss, combining physical activity with a modest calorie deficit from diet is the most effective approach. This calculator shows both your exercise calorie burn and the additional daily diet deficit needed to meet your weekly weight loss target. For example, a moderate pace of 0.5 kg per week requires a daily deficit of 550 calories, which can be split between exercise and dietary changes.
What is the best exercise for weight loss?
The best exercise for weight loss is one you enjoy and can sustain consistently. High-intensity activities like running (MET 9.8), jump rope (MET 10.0), and HIIT (MET 8.5) burn the most calories per minute. However, moderate activities like brisk walking (MET 3.5), cycling (MET 7.5), and swimming (MET 8.0) are also effective when done regularly. Use the activity comparison chart to visualize how different activities compare.
How does weight loss work for different regions (IN, US, UK)?
Weight loss principles are universal across all regions. The 7,700 calories per kg of fat conversion is a scientific constant used worldwide. However, recommended daily calorie intakes vary: India's ICMR suggests 1,600-2,400 kcal/day, the US Dietary Guidelines recommend 1,600-2,400 kcal/day for women and 2,000-3,000 for men, and the UK NHS recommends 2,000 kcal/day for women and 2,500 for men. Always consult local health guidelines for personalized advice.
What is the MET formula and how accurate is it?
The MET (Metabolic Equivalent of Task) formula — Calories per minute = MET × 3.5 × weight (kg) / 200 — is a widely accepted method from the Compendium of Physical Activities used by health professionals worldwide. While individual results vary based on fitness level, body composition, and exercise efficiency, the MET formula provides a reliable estimate for weight loss planning. MET values used here are from the 2011 Compendium.
How long will it take to reach my goal weight?
The time to reach your goal weight depends on your total weight to lose, your chosen pace, and how consistently you exercise. For example, losing 5 kg at a moderate pace of 0.5 kg per week takes approximately 10 weeks. The calculator provides a personalized estimate based on your inputs, including your chosen activity, session duration, and weekly frequency. Results are estimates and individual results may vary.