Calorie Calculator: Daily Calorie Needs from TDEE and BMR
This calorie calculator estimates how many calories you should eat each day to lose, maintain, or gain weight. Enter your weight, height, age, gender, and activity level, and it returns your total daily energy expenditure (TDEE) along with a goal-based target and macro breakdown.
It is built for anyone planning their diet — whether you want a daily calorie target for fat loss, a maintenance number to hold steady, or a surplus for gaining muscle. Under the hood it runs three trusted formulas (Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle) so you can compare your numbers with confidence.
How to Use the Calorie Calculator
Choose your unit system
Select Metric (kg/cm) or Imperial (lbs/ft) at the top. Results recalculate automatically when you switch.
Enter your details
Input your weight, height, and age, then pick your gender. These are the inputs every formula needs.
Set activity or body fat
For TDEE, choose one of five activity levels from Sedentary to Extra Active. On the BMR tab, you can optionally enter your body fat % to unlock the Katch-McArdle formula.
Read your results
Results update instantly as you type. View your TDEE, tap the Lose / Maintain / Gain cards to see the matching calorie target, and read the macro split below.
Features
TDEE with 5 Activity Levels
Pick from Sedentary (×1.2), Lightly Active (×1.375), Moderately Active (×1.55), Very Active (×1.725), or Extra Active (×1.9). Your TDEE is your BMR multiplied by the level you choose.
BMR via Mifflin-St Jeor
Your primary basal metabolic rate uses the Mifflin-St Jeor equation, widely regarded as the most accurate for most adults.
Three-Formula Comparison
On the BMR tab, compare Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle side by side. Katch-McArdle activates once you enter a body fat percentage.
Weight Goal Targets
See calorie targets for losing weight (500 calorie deficit), maintaining, or gaining weight (500 calorie surplus), with a safe floor of 1,200 calories per day for fat loss.
Macro Breakdown
Each goal shows a 30% protein, 45% carbs, and 25% fat split, converted to grams with visual bars for quick comparison.
Metric & Imperial Units
Switch between kilograms/centimeters and pounds/feet/inches with one click. Numbers recalculate automatically.
Optional Body Fat Input
Add your body fat percentage to enable the Katch-McArdle formula, which uses lean body mass for athletic or very lean individuals.
Real-Time Calculation
There is no calculate button — every result updates the instant you type or change any input.
Frequently Asked Questions
How many calories should I eat a day?
Your daily calorie need is your TDEE — the calories you burn each day from your basal metabolism plus activity. Enter your weight, height, age, gender, and activity level, and the calculator shows your maintenance number along with lower targets for losing weight and higher targets for gaining.
What is the difference between TDEE and BMR?
BMR is the calories your body burns at complete rest, just to keep you alive. TDEE includes your BMR plus the calories burned through physical activity and daily movement, so it is always higher than BMR.
Which formula is the most accurate?
The Mifflin-St Jeor equation is generally considered the most accurate for most adults and is used as the primary result here. If you know your body fat percentage, the Katch-McArdle formula may be more accurate, especially for athletes or very lean individuals.
How do I choose the right activity level?
Be honest about your typical week. Sedentary means a desk job with little or no exercise. Lightly Active is light exercise 1-3 days a week, Moderately Active is 3-5 days, Very Active is hard exercise 6-7 days, and Extra Active means very intense exercise plus a physically demanding job.
How many calories to lose or gain weight?
A 500 calorie daily deficit typically leads to about 0.5 kg (1 lb) of weight loss per week, while a 500 calorie surplus supports gradual gain. The calculator applies these targets automatically and enforces a minimum of 1,200 calories per day for fat loss. Always consult a healthcare professional before starting a new diet.
Why do the three formulas give different results?
Each formula uses different coefficients. Mifflin-St Jeor and Harris-Benedict both use weight, height, age, and gender but with different equations, while Katch-McArdle uses lean body mass to account for your muscle-to-fat ratio. Differences of 50-200 calories between formulas are normal.
Is my data stored or shared?
No. All calculations happen entirely in your browser. Your personal information is never sent to any server or stored anywhere.
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