Calorie Deficit Calculator for Weight Loss
Enter your details to estimate your maintenance calories and a daily calorie target for fat loss.
BMR
—
Maintenance Calories
—
Weight-Loss Calories
—
Estimated BMI
—
This calculator gives an estimate, not medical advice. Real calorie needs vary by genetics, medications, hormones, sleep, stress, and tracking accuracy. If you are pregnant, breastfeeding, under 18, or have a medical condition, speak with a qualified healthcare professional before starting a calorie deficit.
How many calories should you eat to lose weight?
A practical starting point for most adults is to eat 300 to 700 calories below maintenance per day. That usually leads to steady fat loss while still allowing enough food for energy, training, and recovery. Your exact number depends on body size, activity level, age, and how fast you want progress.
The calculator above estimates your maintenance calories first (also called TDEE), then subtracts a calorie deficit based on your selected weekly loss target. It is designed as a realistic starting point, not a perfect final answer.
How this calculator works
1) Basal metabolic rate (BMR)
BMR is the energy your body burns at rest. We estimate it with the Mifflin-St Jeor equation:
- Men: BMR = (10 × weight kg) + (6.25 × height cm) - (5 × age) + 5
- Women: BMR = (10 × weight kg) + (6.25 × height cm) - (5 × age) - 161
2) Total daily energy expenditure (TDEE)
We multiply BMR by your activity factor to estimate maintenance calories:
| Activity Level | Multiplier | Typical Profile |
|---|---|---|
| Sedentary | 1.20 | Little or no training, desk-heavy lifestyle |
| Lightly Active | 1.375 | 1-3 sessions per week |
| Moderately Active | 1.55 | 3-5 sessions per week |
| Very Active | 1.725 | Hard training most days |
| Extremely Active | 1.90 | Manual labor + frequent training |
3) Calorie deficit for fat loss
The tool subtracts daily calories based on your selected weekly rate:
- 0.25 kg/week ≈ 275 kcal/day deficit
- 0.50 kg/week ≈ 550 kcal/day deficit
- 0.75 kg/week ≈ 825 kcal/day deficit
- 1.00 kg/week ≈ 1100 kcal/day deficit
What is a good calorie target for weight loss?
For most people:
- Small deficit: 10-15% below maintenance (easy to sustain)
- Moderate deficit: 15-25% below maintenance (best balance of speed + adherence)
- Aggressive deficit: 25%+ below maintenance (short-term only for selected cases)
The most effective target is the one you can stick to for weeks, not just days. Consistency beats intensity.
Macronutrients matter too
Calories drive weight change, but food quality and macros affect hunger, performance, and body composition. A simple framework:
- Protein: 1.6-2.2 g per kg body weight daily to help retain muscle.
- Fat: at least 0.6-0.8 g per kg body weight for hormones and health.
- Carbs: use the remaining calories based on activity and preference.
How to use your result in real life
Week 1-2: Establish your baseline
Eat close to your suggested target, track intake honestly, and weigh yourself daily (same time each morning). Use the weekly average, not single-day fluctuations.
Week 3+: Adjust based on progress
- If average weight is dropping too fast, add 100-150 calories.
- If weight is not moving for 2-3 weeks, reduce by 100-150 calories or increase activity.
- Keep protein high and include resistance training 2-4 times weekly.
Common reasons fat loss stalls
- Portion sizes are underestimated.
- Weekend intake offsets weekday deficits.
- Activity drops as calories drop (fewer steps, lower NEAT).
- Sleep and stress increase water retention.
- Scale noise hides short-term progress.
FAQ
Should I eat the same calories every day?
You can, but you do not have to. Many people prefer a weekly average approach, eating a little more on training days and less on rest days while keeping the weekly total aligned.
Is 1,200 calories safe for everyone?
No. 1,200 is often too low for many adults, especially men, active women, and taller individuals. If your target feels unsustainable, move to a smaller deficit.
How accurate are calorie calculators?
Usually good enough for a starting estimate, but not exact. Think of the output as a testable hypothesis. Track outcomes and adjust by 100-200 calories as needed.
Can I lose weight without tracking calories?
Yes, if habits naturally create a deficit: high-protein meals, more fiber, fewer liquid calories, and consistent meal timing. But tracking often speeds learning and improves precision.
Final takeaways
If you have been asking, “How many calories should I eat for weight loss?”, start with your calculator result, follow it consistently for 2-3 weeks, then adjust based on trend data. Keep protein high, train with resistance, and choose a calorie target you can maintain with your real lifestyle.
Sustainable fat loss is not about perfection. It is about a repeatable system that works for months, not just motivation for a weekend.