Fat Loss Calculator
Calculate how fast you can reach your target weight and how many calories you need each day. A realistic forecast that accounts for metabolic adaptation.
Goal: lose 10 kg
How fast can you lose weight safely?
A safe and sustainable rate of weight loss is 0.5–1 kg per week, corresponding to a daily calorie deficit of 500–1,000 kcal. Faster weight loss is possible in the short term but comes with real risks: muscle mass loss, metabolic slowdown, nutrient deficiencies, and the yo-yo effect.
One kilogram of body fat contains approximately 7,700 kcal of stored energy. At a daily deficit of 500 kcal you lose roughly 0.5 kg of fat per week — about 2 kg per month. Losing 10 kg at this pace takes approximately 5 months.
This calculator also accounts for the fact that metabolism slows as body weight decreases. A lighter body needs less energy to sustain itself, so the rate of weight loss naturally slows over time — this is completely normal and expected.
How does a calorie deficit work?
A calorie deficit means eating fewer calories than your body burns. When you eat below your TDEE, the body draws on its stores — primarily fat — as its energy source.
Mild — ~0.27 kg/week
Best for long-term, sustainable fat loss
Moderate — ~0.45 kg/week
Best option for most people
Aggressive — ~0.64 kg/week
Suitable for shorter cutting phases
Very aggressive — ~0.91 kg/week
Short-term only — monitor carefully
Tips for successful fat loss
Nutrition
- Eat enough protein (1.6–2.2 g/kg) to preserve muscle mass
- Prioritise satiating foods: vegetables, protein, fibre
- Track calories at least initially — awareness is the key
- Avoid banning any food entirely — moderation beats restriction
Training & lifestyle
- Strength train 2–4 times per week to protect muscle mass
- Increase daily movement: walking, stairs, cycling
- Sleep 7–9 hours — sleep regulates hunger hormones
- Take a diet break every 8–12 weeks to manage metabolic adaptation
Most common fat loss mistakes
Using too large a calorie deficit
Start with a moderate 300–500 kcal deficit. Too large a deficit causes muscle loss and the yo-yo effect.
Neglecting protein intake
Eat at least 1.6 g of protein per kg of body weight per day. This protects muscle mass and keeps hunger in check.
Cardio only, no strength training
Strength training is the most important type of exercise during a cut — it signals to the body to preserve muscle.
Weighing too infrequently or too obsessively
Weigh yourself daily in the morning and track the weekly average. Single-day fluctuations of 0.5–1.5 kg are completely normal.
Giving up during a plateau
Weight stalling for 1–3 weeks is normal. Stay on plan or add a little more activity — progress will resume.
Frequently asked questions
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