Which calorie formula is most accurate?

The Mifflin-St Jeor equation is considered the most accurate for most adults and is recommended by the Academy of Nutrition and Dietetics. The Katch-McArdle formula is more accurate for lean individuals with known body fat percentage.

TDEE stands for Total Daily Energy Expenditure — the total calories you burn per day including your BMR plus physical activity. It is the number you should use to set calorie targets for weight goals.

How many calories should I eat to lose weight?

A deficit of 500 calories per day below your TDEE typically produces approximately 0.5 kg (1 lb) of weight loss per week. A 1000 calorie deficit targets ~1 kg per week. Deficits greater than 1000 kcal/day are not recommended without medical supervision.

BMR (Basal Metabolic Rate) is the number of calories your body needs at complete rest to maintain vital functions — breathing, circulation, and cell production. It represents roughly 60–70% of total daily calorie expenditure.

Are calorie calculators accurate?

Calorie calculators provide an estimate based on population averages. Individual metabolism varies by up to 15–20%. Use the result as a starting point and adjust based on real-world results over 2–4 weeks.

Is this calorie calculator free?

Yes — completely free, no sign-up required. Results can be exported to CSV or printed as PDF.

Medical › Nutrition

Calorie Calculator

Calculate your daily calorie needs using the Mifflin-St Jeor and Harris-Benedict equations. Get your BMR, TDEE, and personalised calorie targets for weight loss, maintenance, or muscle gain.

🔥 Calculate Your Daily Calories

Age (years)

Biological Sex

Weight (kg)

Height (cm)

Activity Level

Goal

Formula (both shown in results)

Body Fat % (required for Katch-McArdle)

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Daily Calorie Target

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Suggested Macronutrient Split

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Body Fat % Calculator

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Ideal Body Weight

Find your ideal weight range to set a realistic calorie goal.

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How to Calculate Daily Calorie Needs

Your daily calorie requirement depends on your Basal Metabolic Rate (BMR) — the energy your body needs at complete rest — multiplied by an activity factor to give your Total Daily Energy Expenditure (TDEE). This calculator uses the two most widely validated equations in clinical nutrition alongside the Katch-McArdle formula for those with known body composition data.

Mifflin-St Jeor Equation (Recommended)

The Mifflin-St Jeor equation is considered the most accurate for most people and is recommended by the Academy of Nutrition and Dietetics. It was developed in 1990 and validated across diverse populations:

Men: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
Women: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161

Harris-Benedict Equation (Revised)

The original Harris-Benedict equation (1919) was revised by Roza and Shizgal in 1984. It remains widely used in clinical settings, particularly for hospitalised patients. If you want to compare both equations, our BMR calculator shows all three formulas side by side.

Activity Multipliers (TDEE)

BMR is multiplied by an activity factor (the Harris-Benedict activity multiplier) to estimate TDEE — the total calories burned in a day including exercise and daily movement. Choosing the right activity level is critical for accuracy.

Calorie Targets by Goal

Weight loss (moderate): TDEE − 500 kcal/day → ~0.5 kg/week loss
Weight loss (fast): TDEE − 1000 kcal/day → ~1 kg/week loss
Maintenance: TDEE — sustain current weight
Muscle gain: TDEE + 300 kcal/day — lean bulk with minimal fat gain

For a complete body composition assessment, combine this tool with our BMI calculator and body fat percentage calculator. For fitness-specific nutrition planning, explore our Fitness & Wellness tools.

⚠️ This tool is for informational purposes only. For clinical nutrition planning, consult a registered dietitian or healthcare professional.