Weight Loss Calculator

The mathematical foundation of this calculator relies on standard physiological conversions regarding energy expenditure and fat storage. To lose a kilogram of body fat, researchers generally estimate a cumulative deficit of roughly 7,700 kilocalories. The tool first determines your total Weight to Lose by finding the difference between your current weight and your target weight. Dividing this by your chosen Weight Loss Pace yields the total Weeks required to reach your goal, establishing an estimated Goal End Date.

To find out how sports and physical activities contribute, the calculator evaluates Calories Burned Hourly using Metabolic Equivalents of Task (MET). The formula multiplies your MET value by 3.5, your current weight in kilograms, and a time constant, dividing the result by 200 to yield hourly energy expenditure. By matching your weekly caloric deficit target with specific MET values for activities like running, cycling, or swimming, the tool calculates the exact weekly training hours needed to hit your targets.

Imagine you weigh 80 kg and want to reach a target weight of 75 kg, meaning you have a Weight to Lose of 5 kg. You decide on a steady and sustainable Weight Loss Pace of 0.5 kg per week.

First, calculate the total duration: 5 kg ÷ 0.5 kg/week = 10 weeks to reach your goal. Next, compute your weekly calorie deficit requirement: 0.5 kg × 7,700 kcal/kg = 3,850 calories to burn weekly.

Suppose you choose cycling, which has an average MET value of 8.0 for moderate effort. Using your 80 kg body weight, your hourly calorie burn is calculated as (3,600 × 8.0 × 3.5 × 80) ÷ 120,000 ≈ 672 calories per hour. To achieve your weekly target of 3,850 extra calories burned through cycling, you would need to train for approximately 3,850 ÷ 672 ≈ 5.72 hours per week (about 5 hours and 43 minutes total, split across your weekly sessions).

Prioritize Consistency Over Intensity: Squeezing in multiple moderate-intensity workout sessions per week is generally more sustainable for long-term fat loss than attempting a single exhausting workout that leads to burnout or injury.

Combine Exercise with Nutrition: While exercise accelerates your caloric deficit, diet plays an equally vital role. Ensure your nutritional intake supports your activity levels without completely erasing your deficit.

Recalculate As You Progress: As your body weight decreases, your total daily energy expenditure naturally drops. Re-run your numbers every few weeks to keep your timeline and calorie targets accurate.