Free Calorie Calculator
Calculate your BMR, TDEE, daily calories, and macronutrients for any fitness goal.
What is a calorie calculator?
A calorie calculator is a free online tool that helps you estimate your daily calorie needs using the Mifflin-St Jeor equation, adjusted for your activity level and goal. It runs entirely in your browser — no signup, no app, and no data is ever sent to a server.
In my experience helping friends with their nutrition plans, the single most eye-opening number is always the BMR — most people assume their body burns far fewer calories at rest than it actually does. If you're trying to lose, gain, or maintain weight, the first thing you need is a number: how many calories does your body actually burn in a day? This calculator figures that out using your age, height, weight, gender, and activity level. It calculates your BMR (what you burn at rest) and then adjusts for how active you are to give you your TDEE — total daily energy expenditure. From there you can figure out how many calories to eat for your goal.
How it works
The calorie calculator uses the Mifflin-St Jeor equation, widely regarded as the most accurate BMR formula for the general population. For men, the formula is BMR equals 10 times weight in kilograms plus 6.25 times height in centimeters minus 5 times age plus 5. For women, the formula subtracts 161 instead of adding 5. Your BMR represents the calories your body needs at complete rest just to keep your organs functioning — your heart beating, lungs breathing, cells regenerating, and body temperature maintained. Surprisingly, BMR accounts for 60 to 75 percent of your total daily energy expenditure, which is why understanding it is the foundation of any nutrition plan.
Your TDEE is your BMR multiplied by an activity factor that accounts for your exercise habits, from sedentary to extra active. The five activity levels range from sedentary (desk job, little exercise) at a multiplier of 1.2, up to extra active (strenuous daily exercise or physical labor) at 1.9. For weight loss, we subtract 500 calories from your TDEE to create a weekly deficit of roughly 3,500 calories, enough to lose about one pound per week. For weight gain, we add 500 calories to support muscle growth and healthy mass gain. The calculator also breaks your goal calories into protein, carbohydrates, and fat using the recommended 30-40-30 ratio — 30 percent protein for muscle repair and satiety, 40 percent carbohydrates for energy, and 30 percent fat for hormone production and nutrient absorption. Each macro is displayed in grams so you can plan your meals around tangible targets rather than abstract percentages.
The weight projection feature is one of the most motivating parts of the calculator. If you enter a target weight while in lose or gain mode, the calculator estimates how many days it will take to reach that goal based on your daily deficit or surplus, and shows you the projected calendar date. This transforms an abstract goal into a concrete timeline, helping you stay consistent through your journey. The calculator supports both US units (pounds, feet, inches) and metric units (kilograms, centimeters), with an automatic conversion toggle that preserves your values when switching between systems.
When to use a calorie calculator
A calorie calculator is useful for anyone managing their weight, whether your goal is fat loss, muscle gain, or simple maintenance. It is especially helpful when starting a new diet or fitness routine, as it gives you a science-based starting point for your daily intake rather than guessing or following a generic plan. Athletes use the macro breakdown to tailor their nutrition to their training — increasing carbs before competition, prioritizing protein during muscle-building phases, and adjusting fat intake for endurance sports. The BMR reading alone is valuable for anyone who has wondered why two people of the same weight can have very different calorie needs; height, age, and muscle mass all play significant roles that the Mifflin-St Jeor equation accounts for.
Beyond weight management, the calorie calculator helps with general health awareness. Most people underestimate their calorie intake and overestimate their activity level — having a calculated TDEE provides a reality check. Use it alongside our BMI Calculator to see how your weight category and energy needs relate, the Age Calculator for precise tracking of age-related metabolic changes, and the Sleep Calculator to optimize your rest since poor sleep can disrupt hunger hormones and make weight management harder.
Common mistakes people make
The most common error I see is people setting an activity level too high — "I go to the gym three times a week" does not make you "very active" (that's a 1.725 multiplier). Most people who exercise 3-5 days a week should use "moderately active" (1.55) or even "lightly active" (1.375) if they have a desk job. Overestimating your activity can add 300-500 calories to your TDEE, which completely cancels your deficit. Another big mistake: eating back all your exercise calories. If you burn 300 calories at the gym but eat 300 extra, your net deficit is zero. The BMR vs TDEE confusion is also rampant — I see people trying to eat at their BMR of 1,400 calories when their TDEE is 2,200, which is unnecessarily restrictive and often leads to burnout and bingeing within weeks.
How to use this calculator
- Enter your stats — Fill in your age, gender, height, weight, and activity level. Switch between US and metric units with the toggle.
- Choose your goal — Select whether you want to maintain, lose, or gain weight. If losing or gaining, enter your target weight to see a projected goal date.
- Read your results — Your BMR, TDEE, goal calories, and macronutrient breakdown appear instantly. Use the projected date to track your timeline.
Frequently asked questions
How many calories should I eat per day to lose weight?
A safe calorie deficit for weight loss is 500–750 calories per day below your TDEE (Total Daily Energy Expenditure), producing roughly 1–1.5 pounds of fat loss per week. Eating below 1,200 calories (women) or 1,500 calories (men) is not recommended without medical supervision. Enter your details in the calculator to find your personal TDEE and deficit targets.
How do I calculate my TDEE (Total Daily Energy Expenditure)?
TDEE = BMR × Activity Multiplier. First calculate BMR using the Mifflin-St Jeor equation: for men, BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age + 5. Then multiply by your activity level: sedentary (×1.2), lightly active (×1.375), moderately active (×1.55), very active (×1.725). The calculator does all of this automatically.
How many calories do I need to maintain my current weight?
Maintenance calories equal your TDEE — what you burn in a day accounting for both metabolism and activity. A sedentary 35-year-old woman at 140 pounds and 5'5" burns approximately 1,800–1,900 calories daily. An active man of the same age at 180 pounds and 5'11" burns approximately 2,700–2,900. Enter your stats for your personal estimate.
What is the difference between BMR and TDEE?
BMR (Basal Metabolic Rate) is the calories your body burns at complete rest — just to maintain organ function, breathing, and body temperature. TDEE adds the calories burned through physical activity on top of BMR. BMR is typically 60–70% of TDEE. You should eat at or below your TDEE to maintain or lose weight — not at your BMR, which is too low.
How many calories should a woman eat to lose 2 pounds per week?
Two pounds per week requires a 1,000-calorie daily deficit (since one pound of fat = ~3,500 calories). For most women, this means eating 1,200–1,400 calories per day — which is the safe minimum. If your TDEE is below 2,200, a 2-pound/week deficit may require eating below the safe minimum, making 1–1.5 pounds/week a more realistic goal.
Does the calorie calculator account for exercise?
Yes — select your activity level to include exercise in the TDEE calculation. 'Lightly active' covers 1–3 days of exercise per week; 'moderately active' covers 3–5 days; 'very active' covers 6–7 days of intense exercise. For precise tracking, log specific workouts separately and add those calories back to your daily budget on training days.