Calorie Calculator
Calculate your personalized daily calorie target based on your body stats, activity level, and goal — with projected weight changes over time.
Personal
Target
How Calorie Targets Work
Your body burns a certain number of calories every day — your Total Daily Energy Expenditure (TDEE). This is the sum of your basal metabolism, physical activity, the thermic effect of food, and non-exercise activity thermogenesis (NEAT). To change your weight, you create a gap between what you eat and what you burn.
The widely cited rule of thumb is that one pound of body fat stores approximately 3,500 calories. While the actual value varies (research suggests 3,200–3,750 depending on the individual), it provides a practical framework: a 500 calorie daily deficit translates to roughly one pound of fat loss per week.
This calculator computes your TDEE using the Mifflin-St Jeor equation, applies your chosen deficit or surplus, and projects your weight change over 4, 8, and 12 weeks assuming consistent adherence. Real-world results will vary based on water retention, digestive timing, hormonal cycles, and metabolic adaptation.
Choosing Your Rate
Slow (0.5 lb/week, −250 cal/day): Best for people who are already relatively lean or who want to preserve maximum muscle mass. The mild deficit is easy to sustain and minimizes hunger, fatigue, and metabolic slowdown. Recommended if you're strength training and have less than 15 pounds to lose.
Moderate (1 lb/week, −500 cal/day): The standard recommendation from most dietitians. Balances meaningful progress with manageable restriction. Suitable for most people with 15–50 pounds to lose who aren't at risk of going below safe calorie floors.
Aggressive (1.5 lb/week, −750 cal/day): Appropriate only for people with significant fat to lose (BMI 30+) who can sustain a larger deficit without going below 1,200–1,500 cal/day. Not recommended for extended periods — the risk of muscle loss and metabolic adaptation increases substantially beyond 1 lb/week for most people.
Safe Calorie Floors
Regardless of your deficit, observe minimum calorie floors: 1,200 cal/day for women and 1,500 cal/day for men. Going below these levels makes it difficult to get adequate vitamins, minerals, and macronutrients, and can impair thyroid function, hormonal balance, and immune response.
If your calculated target falls below the safe floor, reduce your rate or increase your activity level rather than eating below the minimum. A smaller deficit sustained over more weeks produces better long-term results than an aggressive deficit that leads to muscle loss and rebound weight gain.
Why Projections Are Approximate
The 4/8/12 week projections assume linear weight change at a constant rate. In reality, weight loss slows over time as your body adapts: a lighter body burns fewer calories (lower BMR), and metabolic adaptation can reduce TDEE by 5–15% beyond what weight loss alone would predict. This is why recalculating your targets every 10–15 pounds or 2–3 months is important.
Weight also fluctuates daily by 2–5 pounds due to water retention, sodium intake, carbohydrate storage (glycogen), digestive contents, and hormonal cycles. Track weekly averages rather than daily weigh-ins to see the real trend beneath the noise.
Frequently Asked Questions
How many calories should I eat to lose weight?
Eat fewer calories than your TDEE. A 500 cal/day deficit produces roughly 1 pound of fat loss per week. Start with a moderate deficit, track your weight for 2–3 weeks, and adjust based on actual results. Never go below 1,200 cal/day for women or 1,500 cal/day for men without medical supervision.
How accurate are calorie calculators?
Online calculators estimate within ±10%. Individual variation in metabolism, NEAT, and nutrient absorption means the number is a starting estimate, not a prescription. Use it as your baseline and calibrate against real-world weight trends over 2–3 weeks.
Should I eat the same calories every day?
The weekly total matters more than daily consistency. Some people prefer calorie cycling — eating more on training days and less on rest days. As long as your weekly average matches your target, the daily distribution is flexible.
What happens if I eat too few calories?
Severe restriction triggers metabolic adaptation: lower metabolic rate, increased hunger hormones, and muscle breakdown for energy. This makes further loss harder and regain more likely. Moderate, sustainable deficits produce better long-term outcomes.
How fast should I lose weight?
0.5–2 lbs/week depending on starting body fat. People with more to lose can sustain larger deficits safely. As you get leaner, slow to 0.5–1 lb/week to preserve muscle. Rapid loss beyond 2 lb/week is rarely fat — it's mostly water and muscle.