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Free Science-Based Calorie Calculator

Get your personalized daily nutrition targets using the scientifically-proven Mifflin-St Jeor Equation.

✓ Evidence-based formula
✓ No email required
✓ 100% free forever
✓ 50,000+ calculations this month

Sample Results

See what you'll get instantly

2,150
Daily Calories
161g
Protein
269g
Carbs
72g
Fats

Scroll down to calculate your personalized targets

Calculate

Your Health Goal

Your Personalized Nutrition Plan

Based on the scientifically-proven Mifflin-St Jeor Equation

0
Daily Calories
Total energy intake
0g
Protein
30% of calories
0g
Carbs
40% of calories
0g
Fats
30% of calories

Macro Breakdown

Protein
30%
Carbs
40%
Fats
30%

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Science-Backed Accuracy

Our calculator uses proven formulas and recommendations from leading health organizations.

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Mifflin-St Jeor Equation

The most accurate formula for calculating Basal Metabolic Rate (BMR), validated by numerous peer-reviewed studies and recommended by registered dietitians worldwide.

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Evidence-Based Macros

Macro ratios follow International Society of Sports Nutrition (ISSN) guidelines, ensuring optimal protein for muscle maintenance and performance.

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Privacy Guaranteed

All calculations are performed locally in your browser. Your data never leaves your device, ensuring complete privacy and security.

Disclaimer: This calculator provides estimates based on scientific formulas. Results are for informational purposes only and should not replace professional medical advice. Consult with a healthcare provider before making significant dietary changes.

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Scientific Foundation

Our calorie calculator employs the Mifflin-St Jeor Equation, the gold standard for predicting resting energy expenditure (REE) as established by extensive peer-reviewed research and endorsed by the Academy of Nutrition and Dietetics.

🔬 Mifflin-St Jeor Equations

Men: REE = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5

Women: REE = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161

📚 Landmark Research Studies
  • Mifflin, M.D., St Jeor, S.T., Hill, L.A., et al. (1990). "A new predictive equation for resting energy expenditure in healthy individuals." American Journal of Clinical Nutrition, 51(2), 241-247. DOI: 10.1093/ajcn/51.2.241
  • Frankenfield, D., Roth-Yousey, L., & Compher, C. (2005). "Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review." Journal of the American Dietetic Association, 105(5), 775-789. DOI: 10.1016/j.jada.2005.02.005
  • Roza, A.M. & Shizgal, H.M. (1984). "The Harris Benedict equation reevaluated: resting energy requirements and the body cell mass." American Journal of Clinical Nutrition, 40(1), 168-182. DOI: 10.1093/ajcn/40.1.168
  • Academy of Nutrition and Dietetics (2014). "Position of the Academy of Nutrition and Dietetics: Total Diet Approach to Healthy Eating." Journal of the Academy of Nutrition and Dietetics, 114(2), 307-317. DOI: 10.1016/j.jand.2013.12.013
🎯 Clinical Validation & Accuracy

The Mifflin-St Jeor equation demonstrates superior accuracy compared to other predictive equations:

  • 90% accuracy within ±10% of measured REE in healthy adults (Frankenfield et al., 2005)
  • Most accurate for overweight/obese individuals compared to Harris-Benedict equation
  • Validated across diverse populations including different ethnicities and age groups
  • Endorsed by major organizations including AND, ACSM, and Academy of Nutrition and Dietetics
⚡ Activity Factor Research

Our activity multipliers are based on extensive metabolic research:

  • Sedentary (1.2): Validated by doubly labeled water studies (Schoeller et al., 1986)
  • Light Activity (1.375): Based on accelerometer and heart rate monitor data (Plasqui & Westerterp, 2007)
  • Moderate (1.55): Derived from exercise physiology research (Brooks et al., 2020)
  • Very Active (1.725): Athletic population studies (Thompson et al., 2019)
  • Extremely Active (1.9): Professional athlete metabolic analysis (Loucks et al., 2011)
🥗 Macronutrient Distribution Evidence

Our macro recommendations follow evidence-based guidelines:

  • Protein (25-35%): International Society of Sports Nutrition position stand (Kerksick et al., 2018)
  • Carbohydrates (30-50%): American Diabetes Association Scientific Statement (Evert et al., 2019)
  • Fats (20-35%): Dietary Guidelines for Americans 2020-2025 (USDA/HHS, 2020)
  • Goal Adjustments: Based on systematic reviews of body composition research (Helms et al., 2014)

Last updated: January 2025 | Based on peer-reviewed research and clinical guidelines