Use Iour free calorie calculator above to find out exactly how many calories you need per day. Whether your goal is weight loss, weight gain, or maintaining your current weight, our daily calorie calculator gives you accurate results based on your age, gender, height, weight, and activity level. Our calorie calculator uses three scientifically proven formulas — Mifflin St Jeor, Revised Harris-Benedict, and Katch-McArdle — to calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE).

Food Energy Converter

Use our free food energy converter below to instantly convert between Calories (kcal), calories (cal), Kilojoules (kJ), and Joules (J). Simply enter a value, select your units, and get the result instantly.

How Many Calories Do I Need Per Day?

The number of calories you need per day depends on several factors including your age, gender, height, weight, and physical activity level. According to the U.S. Department of Health, adult males generally require 2,000–3,000 calories per day to maintain weight, while adult females need around 1,600–2,400 calories per day. However, these are general estimates — our calorie needs calculator gives you a personalized result based on your specific measurements.

General daily calorie guidelines:

These numbers vary significantly based on activity level — a sedentary office worker needs far fewer calories than a professional athlete. Use our calorie intake calculator above for your personalized number.

What Is BMR (Basal Metabolic Rate)?

Your Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest — just to keep you alive. BMR accounts for basic functions like breathing, circulation, cell production, and organ function. Even if you stayed in bed all day doing nothing, your body would still burn this many calories.

BMR is the foundation of every calorie deficit calculator and maintenance calorie calculator. Once you know your BMR, it is multiplied by an activity factor to get your TDEE — the actual number of calories your body needs each day.

Factors that affect BMR:

• Age — BMR decreases with age as muscle mass declines
• Gender — Men typically have higher BMR due to greater muscle mass
• Height and Weight — Larger bodies require more energy
• Muscle Mass — Muscle tissue burns more calories than fat tissue
• Hormones — Thyroid hormones significantly affect metabolic rate
• Body Composition — More muscle = higher BMR

BMR Calculation Formulas

Our calorie calculator uses three different formulas. You can select your preferred formula in the Settings section:

Mifflin St Jeor Equation (Recommended)

The Mifflin St Jeor Equation is considered the most accurate formula for calculating BMR for most people. It was introduced in 1990 and has replaced the older Harris-Benedict equation in most modern calorie calculators.

For Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5

For Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

Revised Harris-Benedict Equation

The Harris-Benedict Equation was one of the first formulas used to calculate BMR, originally developed in 1919 and revised in 1984. It is still widely used but slightly less accurate than the Mifflin St Jeor Equation for most people.

For Men: BMR = 13.397 × weight(kg) + 4.799 × height(cm) − 5.677 × age + 88.362

For Women: BMR = 9.247 × weight(kg) + 3.098 × height(cm) − 4.330 × age + 447.593

Katch-McArdle Formula

The Katch-McArdle Formula is unique because it factors in lean body mass — the weight of your body excluding fat. This makes it potentially the most accurate formula for people who know their body fat percentage, particularly athletes and lean individuals.

Formula: BMR = 370 + 21.6 × (1 − body fat%) × weight(kg)

To use this formula, you need to know your body fat percentage. You can use our Body Fat Calculator to get this number first.

For more information on Basal Metabolic Rate, visit the Wikipedia — Basal Metabolic Rate page.

How to Calculate Your Daily Calorie Needs (TDEE)

Once your BMR is calculated, it is multiplied by an activity factor to get your Total Daily Energy Expenditure (TDEE) — the total calories your body burns per day including exercise and daily activities.

Example: A 30-year-old man, 175 cm tall, 80 kg, with moderate activity:

• BMR (Mifflin St Jeor) = 10×80 + 6.25×175 − 5×30 + 5 = 1,848 calories
• TDEE = 1,848 × 1.55 = 2,864 calories/day

How Many Calories to Lose Weight?

To lose weight, you need to create a calorie deficit — consuming fewer calories than your body burns. Our calorie deficit calculator automatically shows you the recommended deficit for different rates of weight loss.

The science of calorie deficit:

• 1 pound (0.45 kg) of fat = approximately 3,500 calories
• To lose 1 lb per week = deficit of 500 calories/day
• To lose 2 lbs per week = deficit of 1,000 calories/day

Safe weight loss guidelines:

Important: Harvard Health Publications recommends that women consume at least 1,200 calories per day and men consume at least 1,500 calories per day unless supervised by a doctor. Cutting calories too aggressively can lead to muscle loss, nutrient deficiencies, and metabolic slowdown — which can actually make long-term weight loss harder.

It is generally not advisable to lose more than 2 pounds per week, as more rapid weight loss often involves muscle loss and water weight rather than actual fat loss.

How Many Calories to Gain Weight?

To gain weight, you need a calorie surplus — consuming more calories than your body burns. Our weight gain calculator shows recommended surplus for healthy weight gain.

Calorie surplus guidelines:

For those looking to gain muscle rather than just weight, focus on protein intake (1.6–2.2g per kg of body weight), progressive resistance training, and a moderate surplus of 250–500 calories above maintenance. Excessive surpluses lead to unnecessary fat gain.

What Is Maintenance Calories?

Maintenance calories — also called your TDEE — is the number of calories you need to eat each day to maintain your current body weight. If you eat exactly your maintenance calories, your weight will stay the same. This is the baseline number our maintenance calorie calculator provides.

Why knowing your maintenance calories matters:

• It is the starting point for any weight loss or weight gain plan
• It helps you understand how much food your body actually needs
• It prevents both unintentional weight gain and loss
• It allows you to make informed decisions about your diet

Your maintenance calories are not fixed — they change as your weight, age, activity level, and body composition change. If you lose weight, your maintenance calories will decrease. This is why many people hit a weight loss plateau after initial progress.

Calorie Deficit Calculator — How It Works

Our calorie deficit calculator is built into the main calorie calculator above. Here is how to use it effectively:

1. Enter your details — age, gender, height, weight
2. Select your activity level — be honest about your exercise habits
3. Choose your BMR formula — Mifflin St Jeor for most people
4. Click Calculate — your TDEE and all goal-based calorie targets appear instantly

The results show seven calorie targets:

• Maintain Weight — your TDEE
• Mild Weight Loss (−250 cal) — lose 0.5 lb/week
• Weight Loss (−500 cal) — lose 1 lb/week
• Extreme Weight Loss (−1,000 cal) — lose 2 lbs/week
• Mild Weight Gain (+250 cal) — gain 0.5 lb/week
• Weight Gain (+500 cal) — gain 1 lb/week
• Extreme Weight Gain (+1,000 cal) — gain 2 lbs/week

Zigzag Calorie Cycling

Zigzag calorie cycling is an advanced weight loss strategy that involves alternating your daily calorie intake to prevent your body from adapting to a fixed calorie deficit. When you eat the same low number of calories every day for weeks, your metabolism can slow down — sometimes called the “adaptive thermogenesis” effect.

How zigzag calorie cycling works: Instead of eating 1,800 calories every single day, you might eat 2,000 calories on three days and 1,700 calories on four days — both approaches result in the same weekly total but the variation prevents metabolic adaptation.

Our calorie calculator provides two zigzag schedules automatically based on your TDEE. Both schedules have the same weekly calorie total as your standard deficit — they just distribute the calories differently across the week.

Benefits of zigzag calorie cycling:

• Prevents metabolic adaptation and weight loss plateaus
• Allows more flexibility in your diet
• Makes it easier to plan around social events and gatherings
• Psychological benefit — higher calorie days feel like a “break”
• No research evidence that one specific zigzag pattern is superior — consistency matters more

Calorie Counting as a Weight Loss Strategy

Calorie counting is one of the most well-researched and effective methods for weight loss. The fundamental principle is simple: calories in minus calories out determines weight change. However, the practice is more nuanced.

Step-by-step calorie counting guide:

Step 1 — Determine your TDEE Use our calorie calculator above. Be honest about your activity level — most people overestimate how active they are.

Step 2 — Set your calorie goal Choose a deficit that is sustainable. A 500-calorie daily deficit is a good starting point for most people, targeting 1 lb of weight loss per week.

Step 3 — Track your food intake Use a food diary, app, or spreadsheet. Weigh your food when possible — portion sizes are notoriously difficult to estimate accurately.

Step 4 — Monitor progress weekly Weigh yourself at the same time each week (morning, after bathroom, before food). Daily weight fluctuations of 1-3 lbs are normal due to water, food, and waste.

Step 5 — Adjust as needed If you stop losing weight after 3-4 weeks, reduce calories by another 100-200 per day or increase activity.

Quality of Calories Matters

While the calorie deficit is the primary driver of weight loss, the quality of your calories significantly affects your health, hunger levels, and long-term sustainability.

High-quality calorie sources:

• Protein — 4 kcal/gram — Chicken, fish, eggs, legumes, Greek yogurt
• Complex Carbohydrates — 4 kcal/gram — Oats, sweet potato, brown rice, vegetables
• Healthy Fats — 9 kcal/gram — Avocado, nuts, olive oil, fatty fish
• Fiber — 1.9 kcal/gram — Vegetables, fruits, whole grains

Foods that provide empty calories:

• Sugary drinks (soda, fruit juice, energy drinks)
• Processed snack foods (chips, cookies, candy)
• Alcohol — 7 kcal/gram with minimal nutritional value
• Refined white bread and pasta

Studies have shown that foods requiring more chewing — fruits, vegetables, lean meats, whole grains — cause the body to burn more calories during digestion (the thermic effect of food). They also keep you fuller for longer, making it easier to maintain your calorie deficit without feeling hungry.

Calories in Common Foods

Calories Burned From Common Exercises

Sample Meal Plans

1,200 Calorie Meal Plan

1,500 Calorie Meal Plan

2,000 Calorie Meal Plan

How to Lose Weight Without Counting Calories

While our calorie calculator is an effective tool, calorie counting is not the only way to manage weight. Here are evidence-based strategies that work alongside or instead of strict calorie tracking:

1. Eat More Protein Protein is the most satiating macronutrient — it keeps you fuller for longer and has a higher thermic effect than carbs or fat. Aim for 25-30% of your calories from protein.

2. Eat More Fiber High-fiber foods slow digestion, stabilize blood sugar, and reduce overall calorie intake without conscious restriction.

3. Reduce Liquid Calories Drinks like soda, juice, alcohol, and sweetened coffee can add 300-500 calories per day without affecting hunger. Switching to water, black coffee, or unsweetened tea is one of the easiest ways to create a calorie deficit.

4. Use Smaller Plates Research shows that people eat less when food is served on smaller plates, simply due to visual portion perception.

5. Slow Down While Eating It takes approximately 20 minutes for fullness signals to reach the brain. Eating slowly gives your body time to register satiety before you overeat.

6. Prioritize Sleep Sleep deprivation increases ghrelin (hunger hormone) and decreases leptin (fullness hormone), making you eat more the following day. Aim for 7-9 hours per night.

7. Manage Stress Chronic stress elevates cortisol, which increases cravings for high-calorie foods and promotes abdominal fat storage.

Frequently Asked Questions About Calorie Calculator

Q. How many calories should I eat a day? A. The number of calories you should eat per day depends on your age, gender, height, weight, and activity level. Our free calorie calculator gives you a personalized number. As a general guideline, adult women typically need 1,600–2,400 calories and adult men need 2,000–3,000 calories per day to maintain weight.

Q. What is the best formula for calculating daily calories? A. The Mifflin St Jeor Equation is considered the most accurate formula for most people and is the default formula in our calorie calculator. However, the Katch-McArdle Formula can be more accurate for lean individuals who know their body fat percentage.

Q. How many calories should I eat to lose weight? A. To lose 1 pound per week, create a daily calorie deficit of 500 calories below your TDEE. For 0.5 lbs per week, use a 250-calorie deficit. For 2 lbs per week, use a 1,000-calorie deficit. Our calorie calculator for weight loss shows all these targets automatically.

Q. What is a calorie deficit? A. A calorie deficit occurs when you consume fewer calories than your body burns in a day. For example, if your TDEE is 2,500 calories and you eat 2,000 calories, you have a 500-calorie deficit. Over time, this deficit causes your body to use stored fat for energy, resulting in weight loss.

Q. How many calories do I burn in a day? A. The number of calories you burn per day depends on your BMR (the calories burned at rest) multiplied by your activity level. A sedentary adult burns roughly 1.2× their BMR, while a very active person burns up to 1.9× their BMR. Use our calorie calculator to find your exact daily calorie burn.

Q. How many calories should I eat to gain weight? A. To gain 1 pound per week, consume 500 calories above your maintenance calories (TDEE). For muscle gain specifically, aim for a smaller surplus of 200-300 calories combined with regular resistance training to minimize fat gain.

Q. What is a maintenance calorie calculator? A. A maintenance calorie calculator (also called a TDEE calculator) calculates the exact number of calories you need to eat each day to maintain your current body weight. Our calorie calculator automatically shows your maintenance calories as the baseline result.

Q. Is 1,200 calories a day enough? A. For most adults, 1,200 calories per day is at the very low end of safe calorie intake. Harvard Health Publications recommends women eat at least 1,200 calories and men eat at least 1,500 calories per day unless under medical supervision. Eating too few calories can cause muscle loss, nutritional deficiencies, and metabolic slowdown.

Q. What is zigzag calorie cycling? A. Zigzag calorie cycling is a weight loss method where you alternate between higher and lower calorie days while maintaining the same weekly calorie total. This prevents your body from adapting to a consistent low-calorie intake and helps avoid weight loss plateaus. Our calorie calculator provides two zigzag schedules automatically.

Q. How accurate is this calorie calculator? A. Our calorie calculator uses scientifically validated formulas (Mifflin St Jeor, Harris-Benedict, and Katch-McArdle) to estimate your daily calorie needs. These are estimates — actual calorie needs can vary by 10-20% due to individual metabolic differences. Use the results as a starting point and adjust based on your actual weight changes over 2-3 weeks.

Q. How many calories are in a kilogram of fat? A. One kilogram of body fat contains approximately 7,700 calories. Therefore, to lose 1 kg of fat per week, you would need a deficit of approximately 1,100 calories per day — which is aggressive and not recommended for most people. A safer target is 0.5 kg per week (550 calorie deficit per day).

Q. What is the difference between calories and kilocalories? A. In everyday language, “calorie” on food labels refers to kilocalories (kcal). One kilocalorie equals 1,000 small calories. So when a food label says “200 calories,” it technically means 200 kilocalories. Our calorie calculator uses kilocalories (kcal), which is the standard unit for measuring food energy.

For a complete health assessment, also use our BMI Calculator Starbucks Calorie Calculator and Body Fat Calculator.