How Many Calories to Eat to Lose Weight

How many calories should you eat to lose weight? The answer depends on your body, but the formula is simple: eat 15-20% fewer calories than you burn. For most adults, this puts the target somewhere between 1,400 and 2,500 calories per day. The specific number comes from your total daily energy expenditure (TDEE) minus a moderate deficit. Use our calorie calculator to get your personal number in 30 seconds.

But the calorie target is only step one. What you eat within those calories and whether you train during the process determines whether you lose fat or lose muscle. Here is the complete framework.

How Many Calories Should You Eat to Lose Weight?

There is no single calorie number that works for everyone. A 5’2” sedentary woman and a 6’1” active male have vastly different needs, which is why generic advice like “eat 1,500 calories” helps some people and harms others.

The evidence-based approach is to calculate your TDEE, the total number of calories your body burns in a day, and reduce it by 15-20%. For the full math behind this, see our calorie deficit formula guide. For a quick understanding of how TDEE is calculated, see our daily calorie guide.

To show how much the number varies by person, here are three real examples:

• Small sedentary woman (5’3”, 130 lbs, desk job): TDEE ~1,700. Weight loss target: ~1,360 cal/day
• Average moderately active male (5’10”, 180 lbs, trains 4x/week): TDEE ~2,700. Weight loss target: ~2,160 cal/day
• Large active male (6’2”, 220 lbs, trains 5x/week): TDEE ~3,300. Weight loss target: ~2,700 cal/day

All three are in a 20% deficit. All three will lose weight at a similar percentage of their bodyweight per week. But their actual calorie intake ranges from 1,360 to 2,700. This is why personalized calculation matters.

The Three Things That Actually Matter for Weight Loss

The calorie deficit gets you losing weight. But whether you lose fat or muscle depends on two other factors that are equally important.

1. The Calorie Deficit

This is the engine. Without a deficit, weight loss does not happen regardless of food quality, meal timing, or supplement use. A moderate deficit of 15-20% of TDEE is aggressive enough to produce visible results but conservative enough to sustain for months without burnout.

2. Protein Intake

During a deficit, your body looks for energy beyond what you are eating. If protein is low, it pulls from muscle tissue. Increasing protein to 2.0 g/kg bodyweight provides the amino acids needed to protect lean mass, support recovery, and keep you fuller between meals. For a 160 lb (73 kg) person, that is roughly 146g of protein per day. See our protein guide for detailed targets.

3. Resistance Training

Without strength training during a deficit, research suggests that up to 25-30% of weight lost can come from muscle. With consistent resistance training, the vast majority of weight lost comes from fat, and in some cases, beginners can actually gain muscle while losing fat simultaneously.

How Fast Will You Lose Weight?

A sustainable rate of fat loss is 0.5-0.7% of your bodyweight per week. For a 170 lb person, that is roughly 0.85-1.2 lbs per week. For a 220 lb person, that is 1.1-1.5 lbs per week.

At this rate, losing 20 lbs takes approximately 20-30 weeks (5-7 months). This may feel slow, but it is the range that best preserves muscle mass and produces results that actually last. Faster approaches almost always lead to more muscle loss, greater metabolic adaptation, and higher rates of weight regain.

What to expect week by week:

Weeks 1-2: The scale drops quickly, often 3-5 lbs. This feels amazing but is misleading. Most of this initial drop is water and glycogen (stored carbohydrate), not body fat. When you reduce calorie intake, your body depletes glycogen stores, and each gram of glycogen holds roughly 3 grams of water. The actual fat loss during this period is closer to 1-2 lbs.

Weeks 3-4: The scale may stall, bounce up, or barely move. This is the point where most people panic and quit. Fat loss is still happening at the same rate as week 2, but the dramatic water loss has ended and normal water fluctuations from sodium, carbs, hormones, and digestion now mask the underlying trend. This is not a plateau. It is the transition from water loss to pure fat loss.

Week 5 and beyond: Progress becomes steadier and more predictable. Weekly averages trend consistently downward at 0.5-0.7% bodyweight per week. This is the real rate of fat loss, and it continues as long as the deficit is maintained.

Weigh yourself at the same time each morning, record it, and compare the weekly average to the previous week. If your weekly average has not decreased for 2 or more consecutive weeks, reduce intake by 100-200 calories and reassess.

How Low Is Too Low? Calorie Floors for Safe Weight Loss

Every deficit has a floor, a point below which the calorie restriction causes more harm than benefit.

Practical minimums: 1,400 calories per day for women and 1,600 for men. Below these levels, it becomes extremely difficult to get adequate protein, essential fats, vitamins, and minerals from food alone. Nutrient deficiencies, fatigue, and hormonal disruption become increasingly likely.

The Dietary Guidelines for Americans do not recommend sustained intake below 1,200 calories for women or 1,500 for men without medical supervision. Sports nutrition research sets an even more specific threshold: energy availability should not drop below approximately 30 kcal per kilogram of fat-free mass per day. Below this, hormonal function, bone density, immune response, and reproductive health are all compromised.

If your calculated 15-20% deficit puts you below these floors, the deficit is too aggressive for your current TDEE. The solution is not to eat dangerously low calories. Instead, increase your TDEE by adding daily movement (walking, active commuting, household tasks) so that a moderate percentage-based deficit produces a higher absolute calorie target.

What to Do When Weight Loss Stalls

Weight loss is not linear. Stalls happen to everyone, usually every 6-10 weeks. Before assuming the diet has stopped working, check these four things in order.

Recalculate Your Target

As you lose weight, your body burns fewer calories. A person who started at 200 lbs and now weighs 180 lbs has a meaningfully lower TDEE. The deficit that worked at 200 lbs may no longer be a deficit at 180. Plug your updated weight into the calorie calculator every 4-6 weeks.

Check Your Tracking Accuracy

Portion sizes tend to creep up over time. Condiments, cooking oils, and “just a handful” snacks add up. Spend one week re-weighing everything and logging it precisely. The gap between what you think you are eating and what you are actually eating is often 200-400 calories.

Add Daily Movement

Increasing your step count by 2,000-3,000 steps per day can burn an additional 100-200 calories without adding formal exercise sessions. Metabolic adaptation means that many times, what was a deficit for you some time ago, no longer is. This is one of the easiest ways to restore it.

Take a Diet Break

If you have been in a continuous deficit for 8+ weeks, spending 1-2 weeks eating at your current maintenance level may help reset metabolic adaptation and improve adherence. During a diet break, keep training and keep protein high. Simply bring calories back up to your current TDEE. Then resume the deficit.

If body recomposition is your goal, building muscle while losing fat, a moderate deficit combined with strength training and high protein makes this possible, especially for beginners and people returning to training after a break.