Katch Mcardle Macro Calculator

Katch-McArdle Formula:

\[ BMR = 370 + 21.6 \times LBM \] \[ LBM = W \times (1 - BF/100) \] \[ TDEE = BMR \times AF \] \[ DC = TDEE - 500 \] \[ P = \frac{DC \times 0.25}{4} \] \[ C = \frac{DC \times 0.55}{4} \] \[ F = \frac{DC \times 0.20}{9} \]

Weight:

Body Fat Percentage:

Activity Factor:

BMR:

TDEE:

Daily Calories (Deficit):

Protein:

Carbs:

Fat:

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1. What is the Katch-McArdle Formula?

The Katch-McArdle formula calculates Basal Metabolic Rate (BMR) based on lean body mass, making it more accurate for individuals with known body fat percentages. It's particularly useful for athletes and bodybuilders.

2. How Does the Calculator Work?

The calculator uses the Katch-McArdle equations:

Where:

\( BMR \) — Basal Metabolic Rate (kcal/day)
\( LBM \) — Lean Body Mass (kg)
\( W \) — Weight (kg)
\( BF \) — Body Fat Percentage (%)
\( TDEE \) — Total Daily Energy Expenditure (kcal/day)
\( AF \) — Activity Factor (1.2 to 1.9)
\( DC \) — Daily Calories for deficit (kcal/day)
\( P \) — Protein (grams/day)
\( C \) — Carbohydrates (grams/day)
\( F \) — Fat (grams/day)

3. Importance of Macronutrient Calculation

Details: Proper macronutrient distribution is crucial for body composition goals, whether for fat loss, muscle gain, or maintenance. The 25/55/20 ratio provides balanced nutrition while creating a 500 kcal deficit for gradual fat loss.

4. Using the Calculator

Tips: Enter your weight in kg, body fat percentage (use calipers or DEXA scan for accuracy), and select your activity level. For best results, measure body fat under consistent conditions (e.g., morning fasted).

5. Frequently Asked Questions (FAQ)

Q1: Why use Katch-McArdle instead of Harris-Benedict?
A: Katch-McArdle is more accurate for individuals with known body fat percentages as it accounts for lean mass differences.

Q2: What if I don't know my body fat percentage?
A: Use visual estimation guides or consider body measurements. For unknown BF%, the Mifflin-St Jeor formula may be more appropriate.

Q3: Why a 500 kcal deficit?
A: This creates about 0.5kg fat loss per week, a sustainable rate that minimizes muscle loss.

Q4: Can I adjust the macro ratios?
A: Yes, athletes may prefer higher protein (up to 30%), while keto diets would reduce carbs and increase fat.

Q5: How often should I recalculate?
A: Reassess every 4-6 weeks or after significant weight/body composition changes.