Calorie Deficit Calculator for Weight Loss
Use this calculator to estimate how many calories to eat each day for steady fat loss. Enter your details below (metric units).
How many calories should you eat to lose weight?
Weight loss comes down to one core principle: you need to eat fewer calories than your body uses. That difference is called a calorie deficit. This page helps you estimate your daily target using your age, weight, height, sex, and activity level.
A practical range for most people is a deficit of 300 to 700 calories per day. This usually produces a steady loss of about 0.25 to 0.75 kg per week, depending on adherence, body composition, and activity.
How this weight loss calorie calculator works
1) Basal Metabolic Rate (BMR)
Your BMR is the calories your body uses at complete rest (breathing, circulation, cell repair, etc.). This calculator uses 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)
Your TDEE is your maintenance intake (the calories needed to maintain your current weight). We estimate this by multiplying BMR by an activity factor based on your weekly movement and exercise habits.
3) Daily calorie target
To lose fat, we subtract a calorie deficit from your maintenance level. As a rule of thumb, about 7,700 calories corresponds to roughly 1 kg of fat. So if you target 0.5 kg/week, that equals an estimated deficit of about 550 calories per day.
What is a good weekly weight-loss pace?
- 0.25 kg/week: Easiest to sustain, ideal when already lean or diet fatigue is high.
- 0.5 kg/week: Great balance of speed and sustainability for most adults.
- 0.75–1.0 kg/week: Faster progress but harder to maintain; hunger and performance may drop.
In most cases, consistency beats aggression. A moderate deficit kept for months outperforms an extreme deficit you cannot maintain.
Important notes for better accuracy
- Calculator outputs are estimates, not medical diagnoses.
- Track your average weekly weight, not single-day fluctuations.
- If progress stalls for 2–3 weeks, reduce calories by 100–150/day or increase activity.
- Prioritize protein, sleep, hydration, and resistance training to preserve muscle while dieting.
Common mistakes when counting calories
Underestimating portions
Eyeballing often leads to accidental overeating. Use a food scale for calorie-dense foods like oils, nut butters, and snacks.
Ignoring liquid calories
Sweet drinks, alcohol, and even “healthy” smoothies can quickly erase your planned deficit.
Being too aggressive too soon
Severe calorie cuts can increase hunger and reduce training output. A slower, sustainable approach usually wins.
FAQ
How many calories should I cut per day to lose 1 pound per week?
About 500 calories per day is a common estimate for roughly 1 lb (0.45 kg) per week, though real-world results vary.
Can I eat below 1,200 calories?
Very low intakes are generally not recommended without medical supervision. This calculator applies a safety floor (about 1,200 for women and 1,500 for men).
Do I need cardio to lose weight?
No. You can lose weight through diet alone, but adding daily movement and strength training improves health, body composition, and long-term maintenance.
Bottom line
If you have been asking “how many calories do I need to lose weight?”, use the calculator above to get your starting target, then adjust based on real weekly progress. Precision and consistency over time are what produce results.