Calorie Calculator
Calculate exactly how many calories you need per day to reach your weight goal
Your Calorie Results
Calorie Targets by Goal
Compare different calorie levels based on your TDEE
You know your daily target. Kaloria uses AI to instantly log meals from a photo, scan barcodes, and track your progress toward this exact calorie goal -- no manual entry needed.
Try Kaloria FreeUnderstanding Calories and Energy Balance
A calorie is a unit of energy that your body uses to fuel every process from breathing and circulating blood to running and lifting weights. The number of calories you need each day depends on your Basal Metabolic Rate (BMR), which is the energy your body burns at complete rest just to keep organs functioning, and your Total Daily Energy Expenditure (TDEE), which adds in the calories burned through physical activity, digestion, and non-exercise movement. This calculator uses the Mifflin-St Jeor equation, the most accurate widely-used formula for estimating BMR, which has been validated by the American Dietetic Association as superior to older equations like Harris-Benedict.
Weight management follows a straightforward principle: energy balance. When you consume fewer calories than your TDEE, your body taps into stored energy (primarily fat) to make up the difference, resulting in weight loss. A deficit of roughly 500 calories per day yields approximately 0.45 kilograms (one pound) of fat loss per week, while a 1,000-calorie deficit doubles that rate to about one kilogram per week. Conversely, eating above your TDEE creates a surplus that supports muscle growth when combined with resistance training, or leads to fat gain if the surplus is excessive or exercise is absent.
While counting calories is a proven method for weight management, not all calories are equal from a nutritional standpoint. Protein calories (4 kcal per gram) have a higher thermic effect, meaning your body burns more energy digesting protein than it does carbohydrates or fat. Protein also supports muscle preservation during a calorie deficit, which is critical for maintaining your metabolic rate. Carbohydrates (4 kcal per gram) provide rapid energy for workouts and brain function, while fats (9 kcal per gram) support hormone production and nutrient absorption. A balanced approach that meets your calorie target while prioritizing whole foods will produce the best long-term results.
For sustainable results, avoid dropping below 1,200 calories per day for women or 1,500 for men without medical supervision. Very low calorie diets can trigger metabolic adaptation, cause muscle loss, and lead to nutrient deficiencies. Instead, aim for a moderate deficit of 500 calories, pair it with regular physical activity, and recalculate your needs every 5 to 10 pounds of change. Tools like Kaloria can help you stay on track by automatically logging meals and tracking your daily intake against your calculated target, removing the guesswork from calorie counting.
How to Use This Calorie Calculator
- Choose your unit system (Metric or Imperial) using the toggle at the top. All input fields will adjust automatically.
- Enter your age, body weight, and height. These are used in the Mifflin-St Jeor equation to calculate your BMR.
- Select your biological gender and activity level. Be honest about your activity -- overestimating is the most common mistake.
- Choose your goal: lose weight, maintain weight, or gain muscle. This determines whether a calorie deficit or surplus is applied.
- Click "Calculate Calories" to see your BMR, maintenance calories, target intake, a calorie breakdown chart, four goal-specific targets, a timeline projection, and a daily meal breakdown. Use these results to plan your nutrition strategy.
Frequently Asked Questions
How many calories should I eat per day to lose weight?
To lose weight at a safe and sustainable rate, you should eat 500 calories below your TDEE (Total Daily Energy Expenditure). This creates a weekly deficit of 3,500 calories, which translates to roughly 0.45 kg (1 pound) of fat loss per week. For example, if your TDEE is 2,200 calories, aim for 1,700 calories per day. Avoid going below 1,200 calories (women) or 1,500 calories (men) without medical supervision, as extreme deficits can slow your metabolism and cause nutritional deficiencies.
What is the Mifflin-St Jeor equation?
The Mifflin-St Jeor equation is the most accurate widely-used formula for estimating Basal Metabolic Rate (BMR). Published in 1990, it calculates the minimum calories your body needs at rest. The formulas are: For men, BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age in years) + 5. For women, BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age in years) - 161. Your TDEE is then calculated by multiplying BMR by an activity factor between 1.2 and 1.9.
What is the difference between BMR, TDEE, and calorie target?
BMR (Basal Metabolic Rate) is the calories you burn at complete rest just to stay alive -- breathing, circulation, cell repair. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor, representing the total calories you burn in a day including exercise and daily movement. Your calorie target is your TDEE adjusted for your goal: subtract calories for weight loss, keep it equal for maintenance, or add calories for muscle gain. BMR is typically 60-75% of your TDEE.
How do I choose the right activity level?
Be honest and, when in doubt, round down. Sedentary means a desk job with no formal exercise. Lightly Active is 1-3 days of light exercise per week, such as walking or yoga. Moderately Active means 3-5 days of moderate exercise like jogging, cycling, or weight training. Very Active is intense exercise 6-7 days a week. Extra Active is reserved for athletes in training or people with physically demanding jobs like construction. Most people overestimate their activity level, which leads to eating too many calories.
Is a 1,000-calorie deficit safe?
A 1,000-calorie daily deficit can produce rapid weight loss of about 1 kg (2.2 lbs) per week, but it is aggressive and not suitable for everyone. It may lead to increased hunger, fatigue, muscle loss, and metabolic slowdown if sustained for too long. This level of deficit is generally only recommended for individuals with a BMI over 30, under the guidance of a healthcare professional. For most people, a moderate 500-calorie deficit is safer, more sustainable, and better for preserving muscle mass.
Do I need to recalculate my calories as I lose weight?
Yes. As you lose weight, your body requires fewer calories to maintain itself because there is less tissue to fuel. For every 5-10 pounds (2-4.5 kg) lost, you should recalculate your BMR and TDEE. Additionally, metabolic adaptation may cause your body to burn slightly fewer calories than predicted. If your weight loss stalls for more than two weeks despite consistent tracking, reduce your intake by 100-200 calories or increase your activity slightly.
How can I track my calories accurately?
The most effective approach is to use a calorie-tracking app like Kaloria, which uses AI to log meals from photos and barcode scans, eliminating manual data entry. Weigh your food with a kitchen scale for the first few weeks to calibrate your portion awareness. Read nutrition labels carefully and account for cooking oils, sauces, and beverages, which are commonly overlooked. Most people underestimate their intake by 20-50%, so consistent tracking is essential for accurate results.
