1. What is a BMR Calculator with Body Fat?

Definition: This calculator estimates your Basal Metabolic Rate (BMR) using the Katch-McArdle formula which accounts for body composition.

Purpose: It provides a more accurate BMR calculation than weight-only formulas by considering your lean body mass.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( BMR \) — Basal Metabolic Rate (calories/day)
• \( \text{Lean Body Mass} \) — Your weight minus fat mass (kg)

Explanation: The formula calculates calories burned at rest based on your metabolically active tissue (lean mass) rather than total weight.

3. Importance of BMR Calculation

Details: Knowing your BMR helps with weight management, nutrition planning, and understanding your body's energy needs.

4. Using the Calculator

Tips: Enter your total weight in kg and body fat percentage (from measurements, scales, or calipers). Both values are required.

5. Frequently Asked Questions (FAQ)

Q1: Why use body fat percentage instead of just weight?
A: Fat tissue burns fewer calories than lean tissue, so body composition gives a more accurate metabolic rate estimate.

Q2: How accurate is this calculator?
A: It's more accurate than weight-only formulas if you have a reliable body fat measurement (±5-10% error).

Q3: Where can I measure my body fat percentage?
A: Options include skinfold calipers, bioelectrical impedance scales, DEXA scans, or professional assessments.

Q4: Is this my total daily calorie needs?
A: No, this is just your basal rate. Multiply by an activity factor (1.2-2.5) for total daily expenditure.

Q5: Why does my BMR seem low?
A: BMR is only for basic bodily functions at complete rest. Even sleeping burns slightly more calories than BMR.