TDEE & Macro Nutrition Calculator Online Free
Enter sex, age, height, weight and activity level to get BMR via Mifflin-St Jeor, TDEE (BMR × activity factor) and a calorie target for fat loss (−20%), maintenance or lean bulk (+10%). Custom macro percentages convert to protein, carbs and fat grams with protein-per-kg context. No account, no upload of body measurements — pure client-side arithmetic for gym planning and nutrition literacy.
TDEE & Macro Nutrition Calculator In-Browser Workspace
Input data or select files to begin. 100% private, client-side execution with zero server transmission.
How to Use TDEE & Macro Nutrition Calculator
- Step 1: Select sex and age — the sex constant only shifts the BMR intercept.
- Step 2: Enter height and weight in metric (cm/kg) or imperial (ft/lb).
- Step 3: Choose activity factor from sedentary (×1.2) to athlete (×1.9).
- Step 4: Pick goal: cut −20%, maintain, or lean bulk +10%.
- Step 5: Adjust macro percentages (must total 100) and calculate TDEE & grams.
About TDEE & Macro Nutrition Calculator
Basal Metabolic Rate estimates energy at rest. Mifflin-St Jeor (1990) is the equation often preferred in modern dietetics: BMR = 10×weight_kg + 6.25×height_cm − 5×age + s, where s = +5 for males and −161 for females. Total Daily Energy Expenditure multiplies BMR by an activity multiplier: 1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 very active, 1.9 athlete/hard labor — covering NEAT, exercise and thermic effect of food at a coarse grain. Goal targets scale TDEE: a 20% deficit for fat loss, +10% surplus for lean gain; larger cuts increase muscle-loss and adherence risk. Macros are energy-partitioned: protein and carbohydrates provide ~4 kcal/g, fat ~9 kcal/g — so grams = (kcal × percent) / 4 or / 9. Protein-per-kg divides protein kcal ÷ 4 by body weight; training populations often target 1.6–2.2 g/kg. Defaults 30/40/30 are a starting template, not a prescription. Real TDEE varies with NEAT, sleep, thyroid and diet-induced thermogenesis — re-estimate every 4–6 weeks from scale trends rather than treating one number as permanent truth.
Frequently Asked Questions
Why Mifflin-St Jeor over Harris-Benedict?
Mifflin-St Jeor (1990) often predicts resting energy more closely for modern adult samples; results still vary by individual.
Do macro percentages have to sum to 100?
Yes — the tool rejects any split that does not total 100% so grams always match target kcal.
Is a 20% deficit or 10% surplus safe?
Moderate ranges are common for many adults, but medical conditions, pregnancy, underweight or disordered-eating history need clinician guidance.
How often should I recalculate?
Every 4–6 weeks or after a meaningful weight change so TDEE tracks new mass and adaptation.
Is any data stored on a server?
No — inputs and results stay in the browser tab only.