Find out exactly how many calories you need per day to lose, maintain, or gain weight. Get a personalized macro breakdown with multiple diet ratios and a zigzag cycling plan.
Enter your details to get a personalized calorie target
A calorie is a unit of energy. In nutrition, calories refer to the energy people obtain from the food and drink they consume, and the energy they expend through physical activity. The scientific definition of a calorie is the amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius. When we talk about food calories, we are actually referring to kilocalories (kcal), where 1 food calorie equals 1,000 scientific calories.
Your body needs calories to perform every function, from breathing and pumping blood to thinking and exercising. The three macronutrients that provide calories are:
Alcohol also provides calories at 7 calories per gram, but it is not considered a macronutrient because the body does not require it for survival.
Your daily calorie needs depend on several factors, including your age, gender, height, weight, and physical activity level. The process of determining how many calories you need involves two key calculations:
Your BMR is the number of calories your body burns at complete rest to maintain vital life functions. This calculator uses the Mifflin-St Jeor equation, which is widely considered the most accurate BMR formula available and is recommended by the Academy of Nutrition and Dietetics:
Men: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) + 5
Women: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) - 161
Your TDEE is your BMR multiplied by an activity factor that accounts for your daily physical activity. This represents the total number of calories you burn in a day:
| Activity Level | Multiplier | Description |
|---|---|---|
| Sedentary | 1.2 | Little or no exercise, desk job |
| Lightly Active | 1.375 | Light exercise 1-3 days/week |
| Moderately Active | 1.55 | Moderate exercise 3-5 days/week |
| Very Active | 1.725 | Hard exercise 6-7 days/week |
| Extra Active | 1.9 | Very hard exercise, physical job, or training twice/day |
Your TDEE is the maintenance level -- the number of calories you need to eat to maintain your current weight. To lose weight, you eat below this number. To gain weight, you eat above it.
A calorie deficit occurs when you consume fewer calories than your body expends. Since approximately 7,700 calories (or roughly 3,500 kcal per pound) are stored in one kilogram of body fat, creating a sustained deficit leads to weight loss over time.
Here is how different deficit sizes translate to weight loss:
While total calorie intake is the primary driver of weight change, macronutrient distribution affects body composition, performance, satiety, and overall health. This calculator offers four common macro ratios:
A well-rounded split with 30% protein, 40% carbohydrates, and 30% fat. Suitable for most people pursuing general health and moderate fitness goals. Provides adequate carbohydrates for energy while maintaining good protein intake for muscle maintenance.
Higher protein and fat with reduced carbohydrates. Often used for blood sugar management or by those who feel better with lower carb intake. The higher protein helps preserve muscle during weight loss, while increased fat supports satiety.
Emphasizes carbohydrates as the primary fuel source. Popular among endurance athletes, runners, and those with high-volume training. Carbohydrates fuel intense exercise and support glycogen replenishment.
A very low carbohydrate, high fat approach designed to shift the body into ketosis, where it primarily burns fat for fuel. Carbohydrate intake is typically limited to 20-50 grams per day. This approach may support rapid fat loss for some individuals but can be difficult to sustain long-term and may not be suitable for everyone.
Regardless of which macro ratio you choose, adequate protein intake is critical for:
Research suggests that 1.6 to 2.2 grams of protein per kilogram of body weight is optimal for most active individuals.
Medical and nutrition organizations generally recommend losing no more than 0.5 to 1 kg (1 to 2 lbs) per week for safe and sustainable weight loss. Here is why a moderate approach is better than an aggressive one:
If you have a significant amount of weight to lose, the initial rate of loss may be faster due to water weight. This is normal and will typically slow to a steady rate after the first few weeks.
Daily calorie needs vary significantly between individuals. The average adult woman needs approximately 1,600 to 2,400 calories per day, while the average adult man needs 2,000 to 3,000 calories per day. However, your specific needs depend on your age, height, weight, and activity level. Use the calculator above to get a personalized estimate based on the Mifflin-St Jeor equation, which nutrition professionals consider the most accurate formula for estimating BMR.
To lose weight safely, create a calorie deficit of 500 calories per day below your TDEE (maintenance level). This results in approximately 0.5 kg (1 lb) of weight loss per week. A more moderate deficit of 250 calories per day leads to about 0.25 kg (0.5 lb) per week but is easier to sustain. Avoid going below 1,200 calories per day for women or 1,500 for men without consulting a healthcare provider.
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest to maintain basic life functions like breathing, circulation, and cell production. It represents roughly 60-75% of your total daily calorie burn. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor and represents your total daily calorie burn, including physical activity and the thermic effect of food. Your TDEE is the number you use to set calorie goals for weight management.
Macronutrients are the three main nutrient categories that provide energy: protein (4 cal/g), carbohydrates (4 cal/g), and fat (9 cal/g). While total calories determine whether you gain, lose, or maintain weight, the ratio of macronutrients affects your body composition, performance, satiety, and metabolic health. For example, higher protein intake helps preserve muscle during weight loss, while adequate fat intake supports hormone production. This calculator provides four preset ratios (Balanced, Low Carb, High Carb, and Keto) to match different dietary preferences and goals.
Zigzag calorie cycling (also called calorie shifting) involves alternating between higher and lower calorie days while keeping the same weekly average. Instead of eating the same number of calories every day, you might eat more on certain days (like training days) and less on rest days. This approach may help prevent metabolic adaptation during prolonged dieting, reduce psychological feelings of deprivation, and accommodate social events or harder workout days. The calculator provides two zigzag schedules based on your target calories.
A 1,200 calorie diet is generally considered the minimum safe intake for adult women and should only be followed under medical supervision. For men, the minimum recommended intake is typically 1,500 calories per day. Very low calorie diets can lead to nutrient deficiencies, muscle loss, metabolic slowdown, fatigue, hair loss, and hormonal disruption. If the calculator suggests a target near or below these minimums, consider aiming for a smaller deficit and increasing physical activity instead.
This calculator uses the Mifflin-St Jeor equation, which studies have shown to be accurate within approximately 10% for most individuals. It is the formula recommended by the Academy of Nutrition and Dietetics. However, all calorie calculators provide estimates, not exact figures. Individual factors such as genetics, body composition, hormonal status, medications, and metabolic conditions can affect actual calorie needs. Use the calculator result as a starting point and adjust based on real-world results over 2-4 weeks.
This calorie calculator provides estimates based on the Mifflin-St Jeor equation and standard activity multipliers. The results are intended for informational and educational purposes only and should not be interpreted as medical advice, diagnosis, or treatment recommendations.
Individual calorie needs can vary significantly based on factors not captured by this calculator, including medical conditions, medications, metabolic disorders, pregnancy, breastfeeding, and genetics. The calorie targets presented are estimates and may not be appropriate for everyone.
Always consult a qualified healthcare professional, registered dietitian, or physician before making significant changes to your diet, especially if you have any pre-existing health conditions, are pregnant or breastfeeding, or are considering a very low calorie diet. This tool is not a substitute for professional medical advice.