How Many Calories Should I Eat to Lose Weight? (Simple Guide)

Step 1: Calculate Your BMR (Basal Metabolic Rate)

BMR is the number of calories your body burns just existing — breathing, pumping blood, keeping organs running. Even if you lay in bed all day, your body needs this energy.

The most accurate formula is the Mifflin-St Jeor equation:

Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5

Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161

Example: A 30-year-old woman, 5'5" (165 cm), 160 lbs (72.6 kg):

BMR = (10 × 72.6) + (6.25 × 165) − (5 × 30) − 161 = 726 + 1,031 − 150 − 161 = 1,446 calories/day

Step 2: Find Your TDEE (Total Daily Energy Expenditure)

TDEE = BMR × Activity Multiplier. This is what you actually burn per day, including movement.

Activity Level

Description

Multiplier

Example

Sedentary

Desk job, no exercise

× 1.2

Office worker who drives to work

Lightly Active

Light exercise 1–3 days/week

× 1.375

2–3 walks per week, occasional gym

Moderately Active

Moderate exercise 3–5 days/week

× 1.55

Regular gym-goer, active job

Very Active

Hard exercise 6–7 days/week

× 1.725

Athlete, construction worker, daily training

Extra Active

Very hard exercise + physical job

× 1.9

Professional athlete, double sessions

Same example: Our 30-year-old woman walks 3x/week (lightly active): TDEE = 1,446 × 1.375 = ~1,988 calories/day

Step 3: Set Your Deficit

To lose weight, eat fewer calories than your TDEE. The size of the deficit determines how fast you lose:

250 cal/day deficit → ~0.5 lb/week (slow, sustainable)
500 cal/day deficit → ~1 lb/week (the sweet spot for most people)
750 cal/day deficit → ~1.5 lb/week (aggressive, may lose muscle)
1,000 cal/day deficit → ~2 lb/week (only if significantly overweight, with medical supervision)

Our example: 1,988 − 500 = ~1,488 calories/day to lose 1 lb/week

Real-World Examples

Person

TDEE

Target

Loss Rate

Woman, 30, 5'5", 160 lbs, lightly active

1,966

1,466

~1 lb/week

Man, 35, 5'10", 200 lbs, moderately active

2,852

2,352

~1 lb/week

Woman, 45, 5'4", 180 lbs, sedentary

1,656

1,300*

~0.7 lb/week

Man, 25, 6'0", 180 lbs, very active

3,208

2,708

~1 lb/week

* Never go below 1,200 cal (women) or 1,500 cal (men) without medical supervision. The third example is limited to 1,300 for safety.

6 Common Mistakes That Cause Plateaus

Cutting too aggressively. A 1,000+ cal deficit tanks your metabolism within weeks. Your body adapts by burning less. Slow and steady wins.
Not accounting for exercise calories. That spin class burned 300 cal, so you eat them back. But calorie burn estimates are inflated by 30–50%. Eat back half at most.
Ignoring liquid calories. A daily latte (190), afternoon juice (110), and evening wine (150) = 450 invisible calories. That erases your entire deficit.
Weekend blowouts. 5 days in a 500 cal deficit = 2,500 cal saved. One Saturday of “treating yourself” can wipe out the entire week.
Not adjusting as you lose weight. Your TDEE drops as you get lighter. Recalculate every 10–15 lbs lost.
Metabolic adaptation. After 12–16 weeks of dieting, your metabolism slows beyond what weight loss alone explains. Take a 1–2 week diet break at maintenance calories, then resume.

The Simpler Approach

If math isn't your thing, here's a quick estimate: multiply your goal weight (in lbs) by 12. That's roughly your target calories for moderate weight loss with light activity.

Goal weight 150 lbs? 150 × 12 = 1,800 cal/day. It's not precise, but it gets you in the right ballpark without any formulas.