To lose weight, eat about 500 calories a day less than your maintenance calories — what your body burns in a typical day. That deficit adds up to 3,500 calories a week, roughly one pound (0.45 kg) of fat. For most women that means 1,400–1,800 calories a day, and for most men 1,800–2,300.
There is no single number that works for everyone. A 5-foot-2 office worker and a 6-foot-1 construction worker can both be trying to lose weight, yet their targets may differ by 1,000 calories a day. Finding your own number takes three short steps, and this guide works through each one with real numbers you can check.
How Many Calories Should I Eat to Lose Weight?
The short answer is your maintenance calories minus a deficit of 300 to 500 a day. Maintenance calories, also called total daily energy expenditure (TDEE), are what you burn on an average day. Eat that amount and your weight stays roughly stable. Eat less than it, and your body makes up the difference from stored fat.
A free calorie calculator does this arithmetic for you, but understanding the steps means you can sanity-check any number an app gives you — and adjust it when your weight changes.
Step 1: Work Out Your Resting Burn (BMR)
Your basal metabolic rate (BMR) is the energy your body uses at rest, just to breathe, circulate blood, and keep your organs running. It is usually 60 to 70 percent of your daily burn.
Dietitians most often use the Mifflin-St Jeor equation, published in 1990 and validated against measured resting energy in hundreds of adults. It needs only your weight, height, age, and sex:
- Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
- Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
The only difference between the two formulas is the final constant: +5 for men, −161 for women. That 166-calorie gap reflects average differences in muscle mass and body composition. Use kilograms and centimetres: divide pounds by 2.2046 for kilograms, and multiply inches by 2.54 for centimetres.
Step 2: Multiply by Your Activity Level to Get Maintenance
BMR is what you would burn lying in bed all day. Real life adds movement, so multiply BMR by an activity factor to get your TDEE — your maintenance calories:
| Activity level | What it looks like | Multiplier |
|---|---|---|
| Sedentary | Desk job, little or no exercise | 1.2 |
| Lightly active | Light exercise 1–3 days a week | 1.375 |
| Moderately active | Moderate exercise 3–5 days a week | 1.55 |
| Very active | Hard exercise 6–7 days a week | 1.725 |
| Extremely active | Physical job plus daily training | 1.9 |
Be honest here. Most people pick one level too high, which inflates the target and erases the deficit. If you sit most of the day and walk the dog in the evening, you are lightly active, not moderately active.
Step 3: Subtract Your Deficit
Once you have your maintenance number, subtract your target deficit:
| Daily deficit | Weekly deficit | Expected loss |
|---|---|---|
| 250 calories | 1,750 calories | About 0.5 lb (0.2 kg) a week |
| 500 calories | 3,500 calories | About 1 lb (0.45 kg) a week |
| 750 calories | 5,250 calories | About 1.5 lb (0.7 kg) a week |
| 1,000 calories | 7,000 calories | About 2 lb (0.9 kg) a week |
The 3,500-calorie rule comes from the estimate that one pound of body fat stores about 3,500 calories of energy. It is a useful rule of thumb, not a law of physics: real weight loss usually runs a little slower than the rule predicts, because your maintenance calories fall as you get lighter. The CDC describes 1 to 2 pounds a week as a safe, sustainable pace for most adults.
Worked Example 1: A 35-Year-Old Woman, 70 kg, 168 cm, Lightly Active
Follow the three steps with her numbers.
Step 1 — BMR: (10 × 70) + (6.25 × 168) − (5 × 35) − 161 = 700 + 1,050 − 175 − 161 = 1,414 calories a day at rest.
Step 2 — maintenance: 1,414 × 1.375 (lightly active) = 1,944 calories a day. Eat about 1,944 calories and her weight stays roughly stable.
Step 3 — weight-loss target: 1,944 − 500 = 1,444 calories a day, which predicts about 1 pound a week at first. A gentler 250-calorie deficit would give 1,944 − 250 = 1,694 calories a day, or about half a pound a week.
Notice how far this is from the generic “1,200 calories” advice. At 1,200 she would be in a 744-calorie deficit — aggressive, hard to sustain, and close to the floor below which most women should not eat without medical supervision.
Worked Example 2: A 40-Year-Old Man, 90 kg, 178 cm, Lightly Active
Step 1 — BMR: (10 × 90) + (6.25 × 178) − (5 × 40) + 5 = 900 + 1,112.5 − 200 + 5 = 1,817.5 calories a day, rounded to 1,818.
Step 2 — maintenance: 1,818 × 1.375 = 2,499 calories a day (2,499.1 before rounding).
Step 3 — weight-loss target: 2,499 − 500 = 1,999 calories a day, or about 2,000. He can eat roughly 550 more calories a day than the woman in Example 1 and lose at the same pace, simply because he is larger and male — copying someone else’s target is the fastest way to pick the wrong one.
What Is the Lowest Safe Number of Calories?
Most health guidance uses about 1,200 calories a day for women and 1,500 for men as the floor for unsupervised dieting. Below that it becomes genuinely difficult to get enough protein, vitamins, and minerals, and the risk of muscle loss, fatigue, and hormonal disruption rises.
If subtracting 500 from your maintenance takes you below the floor, do not eat below the floor. Take a smaller deficit instead, and add activity to widen it: a 30-minute brisk walk burns roughly 120 to 150 calories.
Why Your Target Number Changes Over Time
Your calorie target is not set in stone. Three things move it. Weight loss itself lowers maintenance: a woman who starts at 80 kg and loses 10 kg burns roughly 100 to 140 fewer calories a day at the same activity level, because her BMR falls by about 100 calories. If the scale stalls after a few months, recalculate with your new weight before assuming the plan has failed — this is the most common cause of a plateau, covered in detail in our guide to what a calorie deficit is. Age lowers it slowly: BMR falls by about 5 calories a year, so a 55-year-old with the same weight, height, and activity as a 35-year-old burns roughly 140 fewer calories a day. Activity is the lever you control: moving from lightly to moderately active on a BMR of 1,414 is worth 1,414 × (1.55 − 1.375) = about 247 extra calories a day, nearly half a pound a week of extra loss without eating less.
How Many Calories to Eat: Quick Reference
These are starting points for a 500-calorie deficit, computed with Mifflin-St Jeor. Your own figure will differ with your exact weight, height, and age — use a calorie calculator for your personal number. The moderately active woman below is the same person as Example 1, one activity level higher: 1,414 × 1.55 = 2,191.7, rounded to 2,192. The man in the last row is worked out step by step in our guide to how to calculate TDEE. If you want the other half of the picture, check your body mass index with our free BMI calculator.
| Person | Maintenance | Target (500 deficit) |
|---|---|---|
| Woman, 35, 70 kg, 168 cm, lightly active | 1,944 | 1,444 |
| Woman, 35, 70 kg, 168 cm, moderately active | 2,192 | 1,692 |
| Man, 40, 90 kg, 178 cm, lightly active | 2,499 | 1,999 |
| Man, 30, 80 kg, 180 cm, moderately active | 2,759 | 2,259 |
FAQ: How Many Calories Should I Eat to Lose Weight?
How many calories should I eat a day to lose weight?
Subtract 300 to 500 calories from your maintenance calories (TDEE). For most women that lands around 1,400 to 1,800 calories a day, and for most men around 1,800 to 2,300.
Is 1,200 calories a day enough to lose weight?
For many women it produces weight loss, but it is the commonly used floor, not a default target. If your maintenance is 1,944, eating 1,200 is a 744-calorie deficit — aggressive and hard to sustain. Most women do better on 1,400 to 1,800 calories.
How many calories should I eat to lose 1 pound a week?
Eat 500 calories a day below your maintenance level. Over a week that is a 3,500-calorie deficit, which the standard rule equates to about 1 pound of fat. Real loss is usually a little slower, so expect roughly 0.5 to 1 pound a week in practice.
How many calories should I eat to lose 2 pounds a week?
Eat 1,000 calories a day below maintenance, a 7,000-calorie weekly deficit. This is the upper end of the safe range and is hard to sustain; it only fits people with a high maintenance, and it should not take you below 1,200 calories (women) or 1,500 (men) a day.
Why am I not losing weight on 1,500 calories?
Either your maintenance is lower than you think, or uncounted food is closing the gap. Recalculate your TDEE with your current weight and an honest activity level, and track everything — including oils, dressings, drinks, and snacks — for two weeks.
Do I need to count calories to lose weight?
Counting is the most reliable way to know you are in a deficit, but it is not the only way. Eating smaller portions, cutting liquid calories, and filling half the plate with vegetables can create a deficit without tracking. Counting simply makes the deficit visible and adjustable when progress stalls.