BMR Calculatorv1.0.0

Use the BMR Calculator to estimate your Basal Metabolic Rate (BMR) and convert it into an activity-adjusted total daily energy expenditure (TDEE). Enter personal data, choose a formula, and select an activity level to calculate daily calorie targets for maintenance, weight loss, or weight gain. Rely on the result unit selector to view values in Calories or Kilojoules, and use the goal selector to apply a simple surplus or deficit.

Follow these steps to produce accurate and consistent results:

• Select units (Imperial or Metric). Enter height and weight in the visible fields. Switch units at any time to convert inputs automatically.
• Enter age and choose sex. Keep age within the supported range for valid results.
• Choose a BMR formula: Mifflin–St Jeor, Revised Harris–Benedict, or Katch–McArdle. If you select Katch–McArdle, enter body fat percent to compute lean body mass.
• Pick an activity level that matches your routine: Sedentary, Somewhat Active, Active, Very Active, Intense, or Extreme. Use the same labels and notes shown in the results table for consistent interpretation.
• Choose a goal (Maintain, Lose, Gain) to apply a standard adjustment to TDEE.
• Choose a results unit (Calories or Kilojoules) to display values in your preferred energy measure.
• Click Calculate to update BMR, activity-adjusted targets, and the results table. Click Reset to restore defaults.

Review the core formulas and logic. Copy these plain-text equations as needed:

• Mifflin–St Jeor (male): BMR = 10 · W + 6.25 · H − 5 · A + 5
• Mifflin–St Jeor (female): BMR = 10 · W + 6.25 · H − 5 · A − 161
• Revised Harris–Benedict (male): BMR = 13.397 · W + 4.799 · H − 5.677 · A + 88.362
• Revised Harris–Benedict (female): BMR = 9.247 · W + 3.098 · H − 4.330 · A + 447.593
• Katch–McArdle: LBM = W × (1 − BF%); BMR = 370 + 21.6 · LBM
• Activity factor (TDEE): Sedentary 1.20; Somewhat Active 1.375; Active 1.463; Very Active 1.55; Intense 1.725; Extreme 1.90
• TDEE = BMR × activity factor
• Goal calories: Maintain = TDEE; Lose = TDEE − 500; Gain = TDEE + 500
• Kilojoules conversion: kJ = Calories × 4.184
• Unit conversions: 1 in = 2.54 cm; 1 ft = 30.48 cm; 1 lb = 0.453592 kg

Verify that your activity selection matches the aligned labels and notes used throughout the interface. Recalculate after meaningful changes in weight, body fat percent, training volume, or routine to keep targets current.

Use the BMR Calculator to understand your metabolic rate and establish calorie targets for diverse health and fitness goals. Apply the formulas to guide nutrition planning, training adjustments, and progress tracking. Rely on the tool as a practical reference to maintain energy balance and achieve results with greater consistency.

• Maintain weight by matching daily calorie intake to your activity-adjusted total energy expenditure (TDEE).
• Reduce weight by creating a sustainable caloric deficit of 500 to 750 calories below TDEE to lose about 1 to 1.5 pounds per week.
• Increase muscle mass by adding 300 to 500 calories above TDEE to support strength training and recovery.
• Compare formulas by viewing Mifflin-St Jeor, Revised Harris-Benedict, and Katch-McArdle side by side to see how each estimates your BMR.
• Assess activity levels by checking calorie ranges for Sedentary, Somewhat Active, Active, Very Active, Intense, and Extreme routines, aligned with clear notes.
• Support medical consultations by sharing calculated values with healthcare providers for dietary or metabolic assessments.
• Design training programs by using BMR and TDEE to set calorie intake for cutting, bulking, or maintenance phases.
• Track progress by recalculating BMR as age, weight, or body composition change, ensuring calorie targets remain accurate.
• Educate yourself by exploring how energy balance depends on BMR, activity factors, and dietary choices.
• Plan recovery days by adjusting intake when physical activity is lower, maintaining energy balance over time.
• Overcome plateaus by modifying calorie intake and activity multipliers when weight loss or gain stalls.

Activity levels correspond to standard multipliers: Sedentary (little or no exercise), Somewhat Active (light exercise 1–3 days per week), Active (moderate exercise 3–5 days per week), Very Active (hard exercise 6–7 days per week), Intense (very hard training or physical job), and Extreme (daily intense exercise or multiple training sessions). Aligning your lifestyle with the correct category helps generate accurate calorie targets.

This tool is intended for informational and educational purposes only. It does not provide medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for any health-related concerns or decisions.