Setting a goal weight is motivating — but knowing exactly how many calories to eat each day to reach that goal by a specific date makes it actionable.
This calculator works backwards from your goal: it determines the total calorie deficit required, divides it by your timeline, and tells you the exact daily intake needed — with a safety flag if the required deficit exceeds healthy limits.
The Energy Maths of Weight Loss
Losing 1 kg of body fat requires a total deficit of approximately 7,700 kcal (3,500 kcal per pound). To lose that kg over 3 weeks, you'd need a daily deficit of ~367 kcal. Over 4 weeks: ~275 kcal/day. The longer your timeline, the smaller and more manageable the daily deficit. This is why patience is one of the most powerful tools in fat loss.
What if My Calculated Deficit is Too Large?
If your goal weight and timeline require a deficit above 1,000 kcal/day, the calculator will flag this as unsafe. The solution: extend your timeline. Losing the same amount of weight over a longer period requires a smaller, more sustainable daily deficit. Most people find that aiming for 0.4–0.6 kg/week leads to the best long-term outcomes.
Why Calorie Needs Change During Your Journey
As you lose weight, your TDEE decreases — you need fewer calories to maintain a lighter body. A 90 kg person and a 75 kg person with otherwise identical stats have significantly different maintenance calories. This is why recalculating every 5–10 kg of weight loss is essential for continued progress.
The Role of Protein in Meeting Your Calorie Target
When eating below maintenance, protein becomes even more critical. High protein intake (1.8–2.2 g/kg) preserves lean muscle mass during a deficit, which maintains BMR and improves body composition outcomes. Prioritising protein also increases satiety, making it easier to adhere to a calorie target.
💡 Expert Tips
- ✓If your required deficit exceeds 750 kcal/day, seriously consider extending your timeline — the difference in final results is minimal, but the difference in muscle retention is significant.
- ✓Pre-logging meals the night before significantly improves adherence to calorie targets — decision fatigue reduces willpower by the evening.
- ✓Eating volume: fill half your plate with vegetables (low calorie, high volume) to feel full while meeting your calorie target.
- ✓Prepare meals in batches — people who batch cook once or twice per week consistently achieve better dietary adherence than those who cook daily.
- ✓Build in one planned 'maintenance day' per week — it reduces the psychological burden of dieting and helps with long-term adherence.
📊 Time to Lose 10 kg at Different Rates
| Daily Deficit | Weekly Loss | Weeks for 10 kg | Assessment |
|---|---|---|---|
| −200 kcal | ~0.18 kg | 55 weeks | Very slow — highly sustainable |
| −350 kcal | ~0.32 kg | 31 weeks | Slow and sustainable |
| −500 kcal | ~0.45 kg | 22 weeks | Optimal rate |
| −750 kcal | ~0.68 kg | 15 weeks | Aggressive — manageable short-term |
| −1,000 kcal | ~0.91 kg | 11 weeks | Maximum safe — monitor closely |
Frequently Asked Questions
How long does it take to lose 10 kg?+
What is the minimum calories I should eat?+
Is my goal weight and timeline realistic?+
How do I avoid the plateau?+
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