How Many Calories Should You Eat to Lose Weight?
To lose weight, you need a calorie deficit. Here's how to calculate your personal target based on TDEE, your goal rate of loss, and your starting weight — with a worked example.
The Calorie Deficit Principle
Weight loss comes down to one equation: calories in vs calories out. When you consistently consume fewer calories than you burn, your body uses stored fat for energy.
1 pound of fat ≈ 3,500 calories
To lose 1 pound per week, you need a 500 calorie/day deficit (500 × 7 = 3,500). To lose 0.5 pounds per week, you need a 250 calorie/day deficit.
Use our Calorie Calculator to find your TDEE and calculate your target intake.
Step 1: Find Your TDEE
Your Total Daily Energy Expenditure (TDEE) is the number of calories you burn each day. It's calculated from your BMR (resting metabolism) multiplied by an activity factor.
See: What Is TDEE and How Do You Calculate It? for the full calculation method.
A quick reference: most sedentary adults burn 1,600–2,200 calories/day. Active adults burn 2,200–3,000+.
Step 2: Choose a Deficit
| Goal | Daily Deficit | Weekly Loss |
|---|---|---|
| Slow cut (sustainable) | 250 cal/day | ~0.5 lb / 0.25 kg |
| Standard cut | 500 cal/day | ~1 lb / 0.45 kg |
| Aggressive cut | 750 cal/day | ~1.5 lbs / 0.7 kg |
| Maximum (short-term only) | 1,000 cal/day | ~2 lbs / 0.9 kg |
Deficits above 750–1,000 cal/day are generally not recommended for sustained periods — they increase muscle loss, nutrient deficiencies, and metabolic adaptation.
Worked Example
Profile: 35-year-old woman, 175 lbs (79.5 kg), 5'5" (165 cm), lightly active. Goal: lose 1 lb/week.
BMR (Mifflin-St Jeor): (10 × 79.5) + (6.25 × 165) − (5 × 35) − 161 = 795 + 1,031 − 175 − 161 = 1,490 cal
TDEE (lightly active, × 1.375): 1,490 × 1.375 = 2,049 cal/day
Target intake (500 cal deficit): 2,049 − 500 = 1,549 cal/day
At 1,549 calories per day with consistent lightly active behavior, she'd lose approximately 1 lb/week — about 12–13 lbs in 3 months.
Why 1,200 Calories Is Often Too Low
Many diet plans target 1,200 calories as a universal "safe minimum." For larger, more active people, this represents a deficit far beyond 500 cal/day — often 800–1,200 cal/day — which accelerates muscle loss and makes the diet unsustainable.
Your minimum intake should generally be no lower than your BMR. Eating less than BMR means you're not consuming enough energy to fuel basic organ function.
How Weight Loss Slows Over Time
As you lose weight, your BMR decreases because there's less body mass to maintain. A 175-lb person has a higher TDEE than a 155-lb person with the same activity level. This means your calorie target needs periodic recalculation — roughly every 10–15 lbs of weight change.
| Starting weight | TDEE (lightly active) | Target at 500 deficit |
|---|---|---|
| 175 lbs | ~2,049 | 1,549 |
| 160 lbs | ~1,950 | 1,450 |
| 145 lbs | ~1,860 | 1,360 |
Recalculating every 15 lbs keeps your deficit accurate and prevents stalls.
Protein and the Calorie Deficit
Within your calorie target, protein intake matters disproportionately during weight loss. Adequate protein (0.7–1g per pound of target body weight) helps preserve muscle mass while in a deficit. At 1,549 calories, prioritizing 100–120g of protein leaves room for carbohydrates and fats while protecting body composition.
Conclusion: Key Takeaways
- Weight loss requires a calorie deficit: ~3,500 cal = 1 lb of fat
- Calculate your TDEE first, then subtract 250–500 cal/day for a sustainable deficit
- For our example (175 lb lightly active woman), target intake is ~1,549 cal/day for 1 lb/week loss
- Don't drop below BMR; don't exceed a 750–1,000 cal/day deficit
- Recalculate every 10–15 lbs as TDEE decreases with weight