How Many Calories Should You Eat to Lose Weight?

"Eat 1,500 calories." "No, 1,200." "Actually, just eat 500 fewer than you burn."

You've heard all of it, and the advice contradicts itself. That's because most of it skips the only step that matters: the right calorie number for weight loss is personal. It's built from your body and your day, not from a headline.

The good news: the math is simple, and you can have your number in the next five minutes. Here's the full logic, plus the guardrails that keep it safe and the fixes for when progress stalls.

Step 1: Find Your Maintenance Number (TDEE)

Everything starts with your TDEE: Total Daily Energy Expenditure. That's the total calories you burn in a day, including your resting metabolism, digestion, daily movement, and workouts.

Eat at your TDEE and your weight stays put. Eat below it and you lose. That's the entire mechanism.

You estimate TDEE in two steps. First, the Mifflin-St Jeor equation gives your resting burn (BMR), using weight in kg and height in cm:

• Men: BMR = 10 × weight + 6.25 × height − 5 × age + 5
• Women: BMR = 10 × weight + 6.25 × height − 5 × age − 161

Then multiply by an activity factor: 1.2 (sedentary), 1.375 (lightly active), 1.55 (moderately active), 1.725 (very active), or 1.9 (extremely active).

Or skip the algebra: our free calorie calculator does both steps and hands you a target. Either way, you need this maintenance number before anything else makes sense.

Quick example. A 38-year-old woman, 170 lb (77 kg), 5'5" (165 cm), lightly active:

BMR = 10 × 77 + 6.25 × 165 − 5 × 38 − 161 = 770 + 1,031 − 190 − 161 = 1,450

TDEE = 1,450 × 1.375 ≈ 1,994 calories/day

Step 2: Subtract a Deficit

Body fat is stored energy: roughly 3,500 calories per pound (about 7,700 per kg). Eat below your TDEE every day and your body makes up the difference from its stores. The deficit size sets your pace:

Daily deficit	Approx. weekly loss	Best for
275 kcal	~0.5 lb (0.25 kg)/week	Smaller bodies, little to lose, easiest to sustain
550 kcal	~1 lb (0.5 kg)/week	The standard pick for most people
825 kcal	~1.5 lb (0.7 kg)/week	Larger bodies or higher starting weights

For the woman in our example (TDEE ≈ 1,994):

• Gentle pace: 1,994 − 275 ≈ 1,720 calories/day
• Standard pace: 1,994 − 550 ≈ 1,445 calories/day
• Aggressive pace: 1,994 − 825 ≈ 1,170 calories/day ← problem, see below

Notice the aggressive option dips under 1,200. That's where the guardrails come in.

The Safety Floors: 1,200 (Women) and 1,500 (Men)

Whatever the deficit math says, don't eat below 1,200 calories a day as a woman or 1,500 as a man without medical supervision.

Below those floors, it gets genuinely hard to cover protein needs and micronutrients from food. Energy craters, workouts suffer, and muscle loss accelerates. The diet also becomes so restrictive that most people abandon it within weeks, which means all that suffering bought nothing.

So for our example: the 825-calorie deficit is off the table. Her real options are ~1,720 or ~1,445, and either one gets her there. The 550 deficit just gets her there faster, at the cost of more hunger.

Rule of thumb: bigger bodies can support bigger deficits. Someone with a TDEE of 3,000 can run 825 comfortably. Someone with a TDEE of 1,800 should stick to 275-550.

Why Aggressive Deficits Backfire

If a 550-calorie deficit loses a pound a week, why not slash 1,500 and lose three? Because your body pushes back, and the pushback is bigger than most people expect.

Hunger scales with the deficit. A moderate deficit produces manageable hunger. A crash deficit produces the kind of hunger that ends in a Friday-night binge that erases the week. Adherence, not ambition, decides who actually loses weight.

Your daily movement quietly drops. On a severe deficit, you fidget less, take the elevator, skip the evening walk, all without deciding to. This non-exercise activity can fall by hundreds of calories a day, silently shrinking the deficit you thought you had.

You lose more muscle. In a steep deficit, especially without enough protein or any strength training, a bigger share of the weight lost is muscle. Muscle is exactly what you want to keep: it drives your resting burn and it's what makes the end result look like the goal.

It doesn't survive real life. Birthdays, travel, stress. A moderate plan absorbs those; a crash plan shatters. The person losing 1 lb (0.5 kg) a week for six months beats the person losing 3 lb a week for three weeks, every time.

Slower is not a consolation prize. Slower is the strategy.

What to Do When the Scale Stalls

At some point, it will. Here's the playbook, in order.

1. Wait it out first. Weight bounces day to day with water, salt, and, for women, cycle phase. A "stall" under two weeks usually isn't one. Compare weekly averages, not single weigh-ins.

2. Audit before you cut. Most stalls are untracked calories creeping back: oils, dressings, bites while cooking, weekend drinks. Tighten tracking for one honest week before changing anything.

3. Recalculate your TDEE. This is the stall everyone forgets. As you lose weight, your body burns less. After 10-15 lb (5-7 kg) lost, your old target may now be close to your new maintenance. Rerun your numbers with your current weight; the free calorie calculator makes that a 60-second job.

4. Adjust one lever at a time. True stall after 2-3 weeks of honest tracking? Either trim intake by 100-200 calories (staying above the floors) or add movement, like a daily 20-30 minute walk. Not both at once; you want to know what worked.

5. Consider a maintenance break. After months of dieting, 1-2 weeks eating at your (new) maintenance level lets hunger settle and life breathe. The scale pausing on purpose beats the diet collapsing by accident.

Putting It All Together

The whole method in four lines:

1. Calculate your TDEE (maintenance calories).
2. Subtract 275, 550, or 825 calories for ~0.5, 1, or 1.5 lb (0.25, 0.5, or 0.7 kg) per week.
3. Never go below 1,200 (women) or 1,500 (men).
4. Track weekly averages, and recalculate as you shrink.

Get your personal starting number from the free calorie calculator, give it three weeks, and let your own results fine-tune it from there.

FAQ

How many calories should a woman eat to lose weight?

Most women lose steadily somewhere between 1,300 and 1,800 calories a day, but the right number depends on her TDEE. Calculate maintenance first, subtract 275-550 calories, and never go below 1,200 a day without medical supervision.

Is 1,200 calories a day enough to lose weight?

For nearly everyone, 1,200 creates a deficit, often a very large one. That's the problem: it's the minimum floor for women, not a smart default. Most people lose just as surely, with far less misery, at a higher intake matched to their own TDEE.

Why am I not losing weight in a calorie deficit?

Usually one of three things. The deficit exists on paper but not in practice (untracked calories), your TDEE estimate was high (overstated activity), or water retention is masking fat loss. Track honestly for two weeks and compare weekly averages before concluding you've truly stalled.

This is general information, not medical advice. If you have a medical condition, talk to your doctor or a registered dietitian before changing your diet.