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Free Calorie & TDEE Calculator

Estimate your BMR and daily calorie needs (TDEE) from age, weight, height, and activity using the Mifflin-St Jeor equation, with targets for losing, maintaining, and gaining.

Works offline once loaded
Maintenance (TDEE)
2,556
calories/day Β· BMR 1,649
Lose weight
2,056
Mild loss
2,306
Maintain
2,556
Mild gain
2,806
Gain weight
3,056
Lose weight (βˆ’0.5kg/wk)
2,056 cal
Mild loss (βˆ’0.25kg/wk)
2,306 cal
Mild gain (+0.25kg/wk)
2,806 cal
Gain weight (+0.5kg/wk)
3,056 cal

Daily macros

Protein
192 g
30%
Carbs
256 g
40%
Fat
85 g
30%

πŸ’‘ Uses the Mifflin-St Jeor equation, the most accurate BMR formula for most people. TDEE multiplies BMR by your activity level. These are estimates β€” adjust based on real-world results over a few weeks. Not medical advice.

Common uses

  • Find Your Calorie Deficit for Weight LossWork out how many calories to eat to lose weight at a steady rate.
  • Find Your Maintenance Calories (TDEE)Estimate the calories that keep your weight stable.
  • Calculate a Lean Bulk SurplusFind the calorie surplus for building muscle without excess fat.
  • Calculate Your BMRFind your basal metabolic rate β€” the calories you burn at complete rest.
  • Set a Calorie Target for Meal PlanningGet a daily calorie number to plan meals and portions around.

How It Works

All calculations run directly in the browser using the Mifflin-St Jeor equation β€” a peer-reviewed formula published in the Journal of the American Dietetic Association β€” with no server requests, no external libraries, and no dependencies beyond React state. The result updates instantly as you type because React's useMemo recomputes the math on every input change.

  1. 1
    Inputs collected and converted
    You enter age, weight, height, sex, and activity level. If you choose imperial units, the tool converts pounds to kilograms (Γ— 0.45359237) and feet/inches to centimeters (Γ— 2.54) before any calculation.
  2. 2
    Mifflin-St Jeor computes BMR
    Your Basal Metabolic Rate is calculated as (10 Γ— kg) + (6.25 Γ— cm) βˆ’ (5 Γ— age) + 5 for males or βˆ’ 161 for females. This is the calories your body needs at complete rest.
  3. 3
    Activity factor scales BMR to TDEE
    BMR is multiplied by an activity factor ranging from 1.2 (sedentary) to 1.9 (extra active), producing your Total Daily Energy Expenditure β€” the calories you actually burn each day with your lifestyle.
  4. 4
    Goal targets and macros derived
    Cutting and bulking targets are computed by subtracting or adding 250–500 kcal from TDEE. A macro breakdown then divides the chosen calorie target across protein, carbs, and fat using fixed caloric densities: 4 kcal/g for protein and carbs, 9 kcal/g for fat.

This tool handles personal health data (age, weight, height, sex) entirely in your browser β€” none of it is sent to any server.

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Frequently Asked Questions