⚖️ Weight Loss Calculator
Calculate how long it takes to reach your target weight – based on your chosen calorie deficit.
⚖️ Weight Loss Calculator
Calculate how long it will take to reach your target weight.
Weight Loss Calculator: When will you reach your goal weight?
Every successful diet starts with a goal. But the most common question isn't how to lose weight, but rather: "How long will it take?" If expectations are far from reality, frustration quickly leads to giving up. Our intelligent weight loss calculator combines thermodynamics with your daily life and calculates exactly how long your fat loss will take with different strategies, down to the day.
The Mathematics of Weight Loss (Thermodynamics)
Forget magic teas, crazy detox cures, or banning carbs after 6 PM. The only physically possible way mammals on this planet lose body fat is through acaloric deficit. This means: You burn more energy in a day than you consume through food.
The 7,000 Calorie Rule
Science states: To lose 1 kilogram of pure body fat, you need to save approx. 7,000 kcal.
Calculation example: If you maintain a clean deficit of 500 kcal every day, you save exactly 3,500 kcal in seven days of the week. This corresponds exactly to a fat loss of 0.5 kilograms per week.
Our calculator uses exactly this formula, utilizes your Basal Metabolic Rate (BMR) from the Calorie Calculator and your activity level to calculate the duration of your goal.
How fast should you lose weight? The Diet Levels
The calculator typically offers you three speeds. We strongly recommend the middle path:
- Slow (-300 kcal / day): The comfortable path. You lose approx. 1.2 kg per month. The advantage? You hardly have to give up anything, have full power in training and risk no yo-yo effect.
- Optimal (-500 kcal / day): The recommended athletic path ("Cut"). You constantly lose approx. 2 to 2.5 kg per month. With this speed, assuming enough protein, you optimally protect your muscles and lose almost pure fat.
- Aggressive (-800+ kcal / day): The crash diet. Should only be chosen for extremely short periods (e.g., vacation prep or severe obesity). Danger: The metabolism adapts, cravings threaten, and muscle tissue is "burned" by the body as an energy source (catabolic state).
Caution: Metabolic Adaptation
Why do so many people lose 3 kilos in two weeks at the beginning and then stagnate for months?
- Water loss: The first 2-3 kilos of a diet are almost always just water and depleted muscle glycogen (carbohydrate stores), not fat!
- Less mass = less consumption: A 100 kg body consumes significantly more energy climbing stairs than an 80 kg body. When you lose 10 kg, your basal metabolic rate drops. You must therefore adjust the calories in our calculator to remain in a deficit.
- Non-Exercise Activity Thermogenesis (NEAT): When the body realizes it is "starving", it subconsciously makes you blink less, gesture less, and you become more sluggish. This way, the brain secretly saves hundreds of calories every day.
The perfect guide to weight loss
Combine the tools on FitScale as follows to securely reach your goal:
- Use the Weight Loss Calculator to determine by which date you must save 500 kcal daily to reach your goal weight.
- Check the Food List (Low Calorie) for volume foods that fill you up extremely well (potatoes instead of rice, broccoli instead of pasta).
- Weigh yourself every day at the same time in the morning on an empty stomach and form the weekly average. Does the average drop by 0.5 kg? Perfect. Does it not drop? Eat 200 kcal less.
- Check once a month with a measuring tape in the Body Fat Calculator to see if you have actually lost fat or just water/muscle.
Losing weight isn't a question of willpower – it's mathematics paired with consistency. Enter your values into the calculator and start the countdown today!