How Many Calories Should I Eat Per Day to Lose Weight?

The single most reliable lever for weight loss is a calorie deficit — consuming fewer calories than your body burns each day. But "eat less" is not a plan; it is a direction. The real question is: how much less, and for how long?

Set the deficit too small and you will lose weight too slowly to stay motivated. Set it too large and you will lose muscle, tank your metabolism, and almost certainly regain the weight within months. This guide gives you the evidence-based numbers to land in the sustainable middle ground.

You will learn how to calculate your Total Daily Energy Expenditure (TDEE), how to size your deficit correctly for your goal, why there are hard minimum calorie floors below which you should never go, and how protein acts as a force-multiplier that makes the entire process easier.

Step 1 — Calculate Your TDEE (Total Daily Energy Expenditure)

Before you can create a deficit, you need to know your maintenance calories — the amount of energy you burn on a typical day. This number is your TDEE.

TDEE is calculated in two stages. First, you estimate your Basal Metabolic Rate (BMR), which is the calories your body burns at complete rest just to keep organs functioning. The Mifflin-St Jeor equation is the gold standard for non-athletic adults:

• 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

Second, you multiply your BMR by an activity multiplier that reflects how much you move throughout the day:

Activity Level Multipliers

The result is your estimated TDEE. For a 35-year-old woman who weighs 75 kg, stands 165 cm tall, and exercises three days per week, the Mifflin-St Jeor equation yields a BMR of roughly 1,530 kcal and a TDEE of about 2,370 kcal at the moderately active multiplier. That is her maintenance level — the starting point for any deficit.

Use our free calorie calculator to get your TDEE in seconds without doing the arithmetic by hand.

Step 2 — Size Your Calorie Deficit Correctly

Once you know your TDEE, subtract a deficit to arrive at your daily calorie target. One pound of body fat stores approximately 3,500 calories of energy. That relationship gives us a reliable planning framework:

• 300 kcal/day deficit → approximately 0.6 lb (0.27 kg) loss per week
• 500 kcal/day deficit → approximately 1 lb (0.45 kg) loss per week
• 750 kcal/day deficit → approximately 1.5 lb (0.68 kg) loss per week
• 1,000 kcal/day deficit → approximately 2 lb (0.9 kg) loss per week

Research consistently shows that a 300–500 kcal daily deficit is the sweet spot for the majority of adults. It is large enough to produce meaningful, visible progress week to week, yet small enough to preserve lean muscle mass, keep energy levels stable, and avoid triggering the aggressive metabolic adaptation that sabotages larger cuts.

Larger deficits (500–750 kcal/day) are appropriate for individuals carrying substantial excess body fat, since they have more stored energy to draw from and can sustain a larger cut without losing muscle at the same rate. Deficits above 1,000 kcal/day are not recommended outside of clinical settings with medical and dietitian supervision.

Calorie Targets by Weight-Loss Goal

The table below shows representative daily calorie targets for different body sizes and weight-loss paces. These are estimates — your individual TDEE will vary based on exact height, weight, age, and activity. Use the values as a starting reference, then adjust based on real-world results after 3–4 weeks.

Note: the Women column assumes a moderately active woman in the 60–80 kg range. The Men column assumes a moderately active man in the 75–100 kg range. Taller, heavier, or more active individuals will have higher TDEE values and correspondingly higher targets.

Minimum Calorie Floors — The Lines You Should Not Cross

Regardless of how much weight you want to lose or how quickly, there are hard lower limits below which calorie restriction becomes genuinely harmful. The most widely cited clinical thresholds are:

• 1,200 kcal/day for women
• 1,500 kcal/day for men

These floors exist because below these levels it becomes nearly impossible to meet micronutrient requirements (iron, calcium, vitamin D, B vitamins) through whole food alone. Deficiencies in these nutrients cause fatigue, bone loss, immune suppression, hormonal dysregulation, and impaired cognitive function — all of which make sustained weight loss harder, not easier.

Very low calorie diets (VLCDs) that go below 800 kcal/day do exist as legitimate medical interventions, but they are conducted under direct physician and dietitian supervision, typically using meal-replacement products formulated to ensure micronutrient adequacy. They are not appropriate as self-directed weight-loss strategies.

Why 1,200-Calorie Diets Backfire for Most People

The number 1,200 kcal has become almost mythically associated with weight loss, appearing in decades of women's magazines and early diet apps as a default target. For most adults, however, a rigid 1,200-calorie diet is not a sustainable strategy — it is a fast route to metabolic adaptation and eventual weight regain.

Adaptive Thermogenesis (Metabolic Slowdown)

When calorie intake drops sharply, the body responds by reducing its energy expenditure through a process called adaptive thermogenesis. This is a survival mechanism: the brain senses scarcity and instructs the body to become more efficient. Studies show that metabolic rate can fall by 15–25% beyond what would be predicted by weight loss alone. This means your TDEE shrinks, your deficit narrows, and progress stalls — even if you are still eating the same number of calories.

Accelerated Muscle Loss

Very low calorie intakes combined with insufficient protein accelerate muscle catabolism. Your body turns to lean tissue for fuel when dietary calories are too low, particularly if resistance training is absent. Less muscle means a lower resting metabolic rate — a compounding disadvantage that makes future weight management harder.

Hunger Hormone Dysregulation

Severe restriction drives up ghrelin (the hunger hormone) and suppresses leptin (the satiety hormone). This hormonal state makes overeating feel almost involuntary once restriction ends, which is a primary driver of the well-documented "yo-yo" dieting cycle.

The Rebound Effect

Population-level data consistently shows that the majority of people who lose weight on very low calorie diets regain it within 1–5 years. The more aggressive the initial restriction, the stronger the biological drive to restore lost weight. A moderate, well- structured deficit avoids triggering this rebound biology as strongly.

The takeaway: if your TDEE is 2,000 kcal and you target 1,200, you are running a 800-calorie daily deficit — far beyond the recommended 300–500 range. Start with a 500-calorie cut to 1,500 kcal. You will lose weight at a clinically healthy rate while protecting your metabolism and muscle mass.

Protein — The Most Important Macronutrient for Weight Loss

Calories determine whether you lose weight. Protein determines the quality of that weight loss — specifically, how much of what you lose is fat versus muscle.

Protein Increases Satiety

Protein is the most satiating of the three macronutrients. It suppresses ghrelin (hunger) and boosts peptide YY and GLP-1 (fullness signals) more strongly than carbohydrates or fat. Studies show that high-protein diets reduce spontaneous calorie intake by 400–500 kcal/day without deliberate restriction — meaning people eat less simply because they feel fuller.

Protein Has a Higher Thermic Effect

The thermic effect of food (TEF) refers to the calories burned digesting and metabolizing what you eat. Protein has a TEF of 20–30%, compared to 5–10% for carbohydrates and 0–3% for fat. In practical terms, if you eat 200 calories of protein, 40–60 of those calories are burned in the process of digestion. This gives protein a meaningful metabolic advantage over other macronutrients.

Protein Preserves Muscle During a Deficit

During calorie restriction, adequate protein intake is the primary dietary tool for preserving lean mass. Research on optimal protein for fat loss consistently points to a target of 0.7–1.0 grams of protein per pound of body weight per day (1.6–2.2 g/kg). For a 75 kg (165 lb) person, this means 115–165 g of protein per day.

High-protein foods to prioritize include chicken breast, turkey, lean beef, eggs, Greek yogurt, cottage cheese, tofu, tempeh, lentils, and protein-rich fish such as tuna and salmon. When protein intake is sufficient, a calorie deficit primarily removes fat — which is the goal.

Calculate your precise protein target alongside your calorie goal using our macro calculator.

Putting It All Together — A Practical Framework

Here is a step-by-step process to set your calorie target and build a sustainable weight-loss plan:

1. Calculate your TDEE. Use the Mifflin-St Jeor equation with the appropriate activity multiplier, or use our calorie calculator for an instant estimate.
2. Choose a deficit size. Start with 300–500 kcal/day for most people. If you have a large amount of weight to lose, you may tolerate up to 750 kcal/day. Never go below the minimum floors (1,200 kcal women, 1,500 kcal men).
3. Set your protein target. Aim for 0.7–1.0 g per pound of body weight. Build meals around protein sources first, then fill in carbohydrates and fat.
4. Track consistently for 3–4 weeks. Use a food scale and a tracking app. Research shows self-reported intake without weighing underestimates actual consumption by 20–50%.
5. Evaluate and adjust. If you are losing more than 1.5 lb/week consistently, add 100–150 kcal to your target. If you are losing less than 0.5 lb/week after four weeks, reduce by 100–150 kcal or increase activity.
6. Plan diet breaks. Every 8–12 weeks of dieting, take 1–2 weeks eating at maintenance. This partially reverses adaptive thermogenesis and improves long-term adherence.

Check your BMI and weight loss projection to set realistic timeline expectations before you begin.

Common Mistakes That Stall Weight Loss

Eyeballing Portions

Visual portion estimation is notoriously inaccurate. Studies consistently show that people underestimate calorie content of familiar foods by 20–50%, particularly for calorie-dense items like nuts, oils, cheese, and peanut butter. A kitchen scale removes this variable almost entirely. Even two weeks of accurate tracking provides invaluable calibration for intuitive eating going forward.

Forgetting Liquid Calories

Drinks are rarely logged with the same discipline as food. Smoothies, fruit juices, specialty coffees, alcohol, and even protein shakes can add 300–600 calories to a day that the tracker never sees. Liquid calories also do not trigger the same satiety response as solid food, making them easy to overconsume without feeling full.

Overestimating Exercise Burn

Fitness trackers and cardio machines consistently overestimate calorie burn, sometimes by 20–50%. Eating back every exercise calorie based on device readouts often eliminates the deficit entirely. A conservative approach: if you did not factor exercise into your TDEE calculation, eat back only 50% of estimated exercise calories.

Weekend Overeating

A 500-calorie deficit on five weekdays can be completely offset by a 750-calorie surplus on each weekend day. Weekly calorie balance is what determines fat loss — not any single day. Allowing a small "flex budget" on weekends (100–200 extra calories) while maintaining awareness prevents total derailment without eliminating social flexibility.

Cutting Carbs Instead of Total Calories

Low-carbohydrate diets work for weight loss primarily because they tend to reduce total calorie intake, not because of any unique metabolic property of carbohydrate restriction. Dropping carbs without reducing overall calories will not create a deficit. And early weight loss on low-carb diets largely reflects glycogen and water depletion, not fat loss — which can be demotivating when the initial rapid drop slows.

Frequently Asked Questions

How many calories should I eat per day to lose weight?

Most adults lose weight effectively by eating 300–500 calories below their Total Daily Energy Expenditure (TDEE). For women this typically falls between 1,400–1,800 kcal/day; for men, 1,700–2,200 kcal/day, depending on body size and activity level. Never go below 1,200 kcal (women) or 1,500 kcal (men) without medical supervision. Use our calorie calculator to get your personalized target.

What is TDEE and how do I calculate it?

TDEE stands for Total Daily Energy Expenditure — the total calories your body burns in 24 hours including all movement and exercise. It is calculated by multiplying your Basal Metabolic Rate (BMR) by an activity multiplier ranging from 1.2 (sedentary) to 1.9 (very active). The Mifflin-St Jeor formula is used to estimate BMR and is the most validated equation for non-athletic adults. Our calorie calculator applies this automatically.

How big should my calorie deficit be?

A deficit of 300–500 calories per day produces 0.5–1 lb of fat loss per week and represents the optimal range for most people because it preserves muscle, maintains energy, and is sustainable long term. Larger deficits up to 750 kcal/day can work for people with significant excess fat but increase muscle-loss risk and metabolic adaptation. Deficits above 1,000 kcal/day require clinical supervision.

Is a 1,200-calorie diet safe for weight loss?

For most adults, a strict 1,200-calorie diet is too aggressive. It triggers adaptive thermogenesis (metabolic slowdown), accelerates muscle loss, risks micronutrient deficiencies, and increases the likelihood of rebound weight gain. It may be appropriate for a petite, sedentary woman under medical supervision, but should not be a default starting point. A moderate 500-calorie deficit from your personal TDEE is a far better first step.

How much weight will I lose eating 500 fewer calories per day?

A 500-calorie daily deficit creates approximately 3,500 calories of deficit per week, which corresponds to roughly 1 lb (0.45 kg) of fat loss per week. In practice, early weight loss is faster due to water and glycogen depletion, and the rate slows over time as TDEE decreases with your lighter body weight. Consistent 1 lb/week loss over six months yields roughly 24–26 lb of total fat loss.

Does eating more protein help with weight loss?

Yes, significantly. Protein is the most satiating macronutrient, reducing hunger hormones and increasing fullness signals. It also has the highest thermic effect (20–30%), meaning your body burns more calories digesting it compared to carbs or fat. Targeting 0.7–1.0 g of protein per pound of body weight preserves muscle during a deficit and reduces the calorie cost of the diet through its metabolic effects.

Should I eat back calories burned through exercise?

It depends on how you calculated your TDEE. If you used an activity multiplier that accounts for your exercise (e.g., moderately active at × 1.55), those calories are already included — do not eat them back. If you used a sedentary TDEE and exercise on top, eat back 50–75% of estimated exercise calories to stay in your target deficit range while accounting for the fact that wearable devices overestimate burn.

Why am I not losing weight even in a calorie deficit?

The most common reasons are underestimating food intake (research shows self-reported intake is often 20–50% below actual consumption), overestimating exercise burn, and water retention masking true fat loss. Metabolic adaptation after prolonged dieting also reduces TDEE. Weigh food with a kitchen scale, track consistently for 3–4 weeks, and see a physician if there is still no progress, as thyroid disorders and other hormonal conditions can impair weight loss.

The Bottom Line

Sustainable weight loss is built on three pillars: an appropriate calorie deficit (300–500 kcal/day below your TDEE), sufficient protein to protect muscle (0.7–1.0 g per pound of body weight), and consistency over weeks and months rather than days. Chasing large deficits or rigid 1,200-calorie targets reliably produces short-term loss followed by metabolic adaptation, muscle loss, and eventual weight regain.

Start by calculating your TDEE, subtract 300–500 calories, prioritize protein at every meal, and track accurately for 3–4 weeks before making any adjustments. This approach is less dramatic than crash dieting — but it is the approach that works and keeps working long after the initial motivation fades.

Ready to get your numbers? Use our calorie calculator to calculate your TDEE and daily calorie target in under two minutes, then pair it with the macro calculator to dial in your protein, carb, and fat split.