Calorie Calculator
Find out exactly how many calories you need per day to reach your weight loss, maintenance, or muscle-building goals.
How Many Calories Should You Eat Per Day?
The number of calories you need each day depends on several factors including your age, gender, weight, height, and activity level. Our calorie calculator uses the Mifflin-St Jeor equation, which is considered the most accurate formula for estimating calorie needs in the general population.
Your calorie needs are first calculated as your Basal Metabolic Rate (BMR) -- the calories your body burns at complete rest -- and then adjusted for your daily activity level to determine your Total Daily Energy Expenditure (TDEE). From there, your calorie target is adjusted based on whether you want to lose weight, maintain, or gain muscle.
How to Calculate Calories for Weight Loss
To lose weight, you need to create a calorie deficit by eating fewer calories than your body burns. A deficit of 500 calories per day typically results in about 1 pound (0.45 kg) of weight loss per week, which is considered a safe and sustainable rate.
Key principles for calorie-based weight loss:
- Moderate deficit: A 500-calorie daily deficit is ideal for most people. Larger deficits can lead to muscle loss and metabolic slowdown.
- Minimum intake: Women should not go below 1,200 calories and men should not go below 1,500 calories per day without medical supervision.
- High protein: Eating 40% of your calories from protein helps preserve muscle mass during weight loss.
- Track progress: Weigh yourself weekly and adjust calories if you are not seeing results after 2-3 weeks.
Understanding Macros and Calorie Quality
Not all calories are created equal when it comes to body composition and performance. Your calorie intake should be split into three macronutrients:
- Protein (4 cal/gram): Builds and repairs muscle tissue. Has the highest thermic effect, meaning your body burns more calories digesting protein than carbs or fat.
- Carbohydrates (4 cal/gram): Your body's primary energy source. Essential for high-intensity exercise and brain function.
- Fat (9 cal/gram): Necessary for hormone production, vitamin absorption, and cellular health. Should make up at least 20% of total calories.
Calories for Muscle Gain
Building muscle requires a calorie surplus -- eating more than your body burns. The size of your surplus determines how fast you gain weight and how much of that gain is muscle vs. fat:
- Lean gain (+250 cal): Slower but cleaner gains with minimal fat accumulation. Best for intermediate and advanced lifters.
- Standard bulk (+500 cal): Faster muscle growth but with more fat gain. Better for beginners who can build muscle more quickly.
Regardless of surplus size, consistent resistance training and adequate protein intake (0.8-1g per pound of bodyweight) are essential for maximizing muscle growth.
Frequently Asked Questions
How many calories should I eat a day?
The number of calories you should eat daily depends on your age, gender, weight, height, and activity level. On average, adult women need 1,600-2,400 calories per day and adult men need 2,000-3,000 calories per day. Use our calculator above for a personalized estimate.
How many calories should I eat to lose weight?
To lose weight, eat 500 calories less than your TDEE. This creates a deficit that typically results in about 1 pound of weight loss per week. Never go below 1,200 calories (women) or 1,500 calories (men) without medical supervision.
What is a calorie deficit?
A calorie deficit occurs when you consume fewer calories than your body burns. This forces your body to use stored energy (fat) for fuel, resulting in weight loss. A moderate deficit of 300-500 calories per day is recommended for sustainable fat loss.
How do I calculate my calorie needs for muscle gain?
For muscle gain, add 250-500 calories above your TDEE. A lean bulk (+250 cal) minimizes fat gain, while a standard bulk (+500 cal) supports faster muscle growth. Pair your surplus with resistance training and adequate protein.
Are all calories the same?
While a calorie is a unit of energy regardless of the source, the quality of calories matters. Protein has a higher thermic effect and supports muscle building. Aim for nutrient-dense whole foods for the majority of your intake.