Here are some key body fitness formula:

1. Body Mass Index (BMI)

BMI = weight (in kg) / height (in meters)²

2. Basal Metabolic Rate (BMR)

BMR (men) = 66 + (6.2 x weight in lbs) + (12.7 x height in inches) - (6.8 x age in years)

BMR (women) = 655 + (4.35 x weight in lbs) + (4.7 x height in inches) - (4.7 x age in years)

3. Daily Caloric Needs

Daily caloric needs = BMR x activity multiplier

Activity multiplier:

- Sedentary (little or no exercise): 1.2

- Lightly active (light exercise/sports 1-3 days/week): 1.375

- Moderately active (moderate exercise/sports 3-5 days/week): 1.55

- Very active (hard exercise/sports 6-7 days a week): 1.725

- Extremely active (very hard exercise/sports & physical job or 2x training): 1.9

4. Body Fat Percentage

Body fat percentage = (body fat weight / total body weight) x 100

5. Lean Body Mass (LBM)

LBM (men) = total body weight - body fat weight

LBM (women) = total body weight - body fat weight

6. Waist-to-Hip Ratio

Waist-to-hip ratio = waist circumference / hip circumference

7. Heart Rate Zones

Heart rate zones:

- Zone 1 (50-60% max HR): warm-up, recovery

- Zone 2 (60-70% max HR): endurance training

- Zone 3 (70-80% max HR): aerobic training

- Zone 4 (80-90% max HR): anaerobic training

- Zone 5 (90-100% max HR): maximum effort

Remember, these formulas are general guidelines and may vary depending on individual factors such as age, sex, and fitness level. Always consult with a healthcare professional or certified fitness expert before starting any new exercise or nutrition program.