1. What is BMR?

Basal Metabolic Rate (BMR) is the number of calories your body needs to maintain basic physiological functions at rest. It accounts for 60-75% of daily calorie expenditure.

2. How Does the Calculator Work?

The calculator uses the Mifflin-St Jeor equations:

Where:

• \( weight \) — Body weight in kilograms
• \( height \) — Height in centimeters
• \( age \) — Age in years
• \( gender\_factor \) — +5 (men) or -161 (women)
• \( activity\_factor \) — Multiplier based on activity level

Explanation: The equation estimates your resting energy expenditure and then adjusts for activity level and a 500 kcal deficit for weight loss.

3. Importance of BMR Calculation

Details: Knowing your BMR helps create personalized diet plans for weight loss, maintenance, or gain. A 500 kcal daily deficit typically results in about 0.5 kg (1 lb) weight loss per week.

4. Using the Calculator

Tips: Enter your weight in kg, height in cm, and accurate age. Select your gender and activity level. For best results, measure weight in the morning after using the bathroom.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculator?
A: It provides a good estimate (±10%) for most people. Individual variations in muscle mass, body composition, and metabolism affect actual needs.

Q2: Why subtract 500 calories?
A: A 500 kcal daily deficit creates about 3500 kcal weekly deficit, which typically results in 0.5 kg (1 lb) of fat loss per week.

Q3: Should I eat below my BMR?
A: Generally no - eating below BMR may trigger starvation responses. The deficit should come from your total daily energy expenditure (TDEE).

Q4: How often should I recalculate?
A: Recalculate every 5-10 kg of weight loss, as BMR decreases with weight loss.

Q5: What if I'm not losing weight at this calorie level?
A: You may need to adjust your activity factor or calorie intake as metabolic adaptation occurs during weight loss.