Macro Calculator

Total Daily Energy Expenditure (TDEE) is the total number of calories you burn in a day, accounting for your basal metabolic rate (BMR) plus all physical activity — exercise, walking, daily movement, and even digesting food. TDEE is the most important number for weight management: eating at your TDEE maintains your current weight, eating below it causes fat loss, and eating above it causes weight gain. Unlike BMR alone, TDEE reflects your real-world energy needs, which is why getting your activity level right is critical for accurate results.

The Mifflin-St Jeor formula is a scientifically validated equation for estimating Basal Metabolic Rate (BMR) — the calories your body needs at complete rest. For men: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5. For women: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161. Developed in 1990, it's considered more accurate than the older Harris-Benedict formula for most modern adults, and is widely used by registered dietitians and sports scientists. TDEE is then calculated by multiplying BMR by an activity factor ranging from 1.2 (sedentary) to 1.9 (extra active).

General recommendations are 0.7–1.0g per pound of bodyweight (1.6–2.2g/kg). Higher protein intake (1.0g/lb) is beneficial during weight loss to preserve muscle mass while in a calorie deficit, and is important for those aiming to build muscle. A more moderate intake of 0.8g/lb is sufficient for weight maintenance when not in a significant deficit. The minimum recommended dietary allowance (RDA) of 0.36g/lb (0.8g/kg) is considered a floor for sedentary adults to prevent deficiency, but is well below what research supports for active individuals or those with fitness goals.

Calculated TDEE values are estimates with a typical individual variance of ±10–20%. The Mifflin-St Jeor formula works best as a starting point. The most common sources of error are: overestimating activity level (the single biggest variable), inaccurate body measurements, and significant deviations in individual metabolism. Track your weight daily and calculate a 7-day average over 2–4 weeks. If your weight isn't changing as expected, adjust your calorie target by 100–200 calories per day and reassess. Real-world feedback is more accurate than any formula.

A 500 calorie/day deficit yields approximately 1 lb of fat loss per week (3,500 calories ≈ 1 lb of fat). A 250 calorie/day deficit yields about 0.5 lb/week — a more sustainable and muscle-preserving rate, especially for those close to their goal weight. Deficits above 750–1,000 calories/day significantly increase the risk of muscle loss, nutrient deficiencies, and metabolic adaptation, and are generally not recommended without medical supervision. Most health professionals recommend staying within a 500–750 calorie/day deficit for sustainable fat loss while preserving lean mass.

Calories determine whether you gain, lose, or maintain weight — it's fundamentally a matter of energy balance. Macros determine body composition: how much of the weight change is fat versus muscle. Tracking both gives the best outcomes. If you're new to nutrition tracking, start with just hitting your daily calorie target. Once that's consistent, add protein as the next priority — it's the macro with the greatest impact on muscle preservation and satiety. Carbs and fats can then be adjusted based on personal preference, energy levels, and dietary style. Many successful people simply track calories and protein without worrying much about carb/fat splits.