Metabolic Calculator

We measure BMI to give you a quick sense of whether you’re underweight, normal, overweight or obese.

• Convert height to meters: height_m = height_cm / 100 (e.g. 175 cm → 1.75 m)
• Plug into the formula: BMI = weight_kg ÷ (height_m × height_m) (e.g. 63.6 kg ÷ (1.75 m × 1.75 m) ≈ 20.8)

Learn more about BMI: CDC – BMI

Your BMR is the calories your body needs at rest to keep your organs running. We offer two common formulas:

• Mifflin–St Jeor
  Male Physiology: BMR = (10 × weight_kg) + (6.25 × height_cm) − (5 × age) + 5
  Female Physiology: BMR = (10 × weight_kg) + (6.25 × height_cm) − (5 × age) − 161
  Undisclosed Physiology: We average the male and female physiology calculations.
  
• Harris–Benedict
  Male Physiology: BMR = 88.362 + (13.397 × weight_kg) + (4.799 × height_cm) − (5.677 × age)
  Female Physiology: BMR = 447.593 + (9.247 × weight_kg) + (3.098 × height_cm) − (4.330 × age)
  Undisclosed Physiology: We average the male and female physiology calculations.
  

Lean Body Mass is the weight of everything in your body except fat – your muscles, bones, organs and water – and it’s key for tailoring nutrition and fitness plans.

• Direct: LBM = weight_kg × (1 − bodyFatPercent ÷ 100)
• Estimated (Boer formula):
  • Male Physiology: LBM = 0.407 × weight_kg + 0.267 × height_cm − 19.2
  • Female Physiology: LBM = 0.252 × weight_kg + 0.473 × height_cm − 48.3
  • Undisclosed Physiology: We average the male and female physiology calculations.

TDEE stands for Total Daily Energy Expenditure. It’s the total number of calories you burn each day, combining your resting needs (BMR) with your activity level.

• Choose an activity factor:
  • Sedentary (little or no exercise): 1.2
  • Lightly active (light exercise): 1.375
  • Moderately active (moderate exercise): 1.55
  • Very active (hard exercise): 1.725
  • Extra active (very hard exercise): 1.9
• Calculate: TDEE (cal/day) = BMR × activityFactor

If you don’t select an activity level, we default to 1 (no adjustment).
Learn more: What Is TDEE?

• Maintain weight: Calories = your estimated TDEE
• Lose weight: Calories ≈ TDEE − 15–20%
• Gain weight: Calories ≈ TDEE + 15%
• Chronic illness support: Calories = TDEE + 10 × weight (kg)
• Ketogenic support: Calories ≈ 90% of TDEE
• Diabetes support: Calories ≈ TDEE − 200 kcal
• Longevity support: Calories ≈ TDEE − 300 kcal

Adjusting your calorie intake relative to your TDEE can help you meet your goals safely. For example, a 15–20% deficit for weight loss typically leads to ~0.5–1 lb (0.2–0.45 kg) lost per week.
Learn more about calorie targets: Mayo Clinic

When you build your plan, we first determine your total daily calories—adjusted for your goal (lose, gain, maintain, etc.) or your chosen diet pattern. Then, to translate calories into grams of protein, carbohydrates, and fat, we apply one of two sets of preset ratios:

Diet-Based Ratios (if you’ve picked a diet profile)

• Standard American: 20% protein / 50% carbs / 30% fat
• Vegan: 20% protein / 55% carbs / 25% fat
• Mediterranean: 25% protein / 50% carbs / 25% fat
• Paleo: 25% protein / 40% carbs / 35% fat
• Ketogenic: 15% protein / 5% carbs / 80% fat

Goal-Based Ratios (if you’ve selected a fitness or therapeutic goal)

• Maintain weight: 25% protein / 50% carbs / 25% fat
• Weight loss: 30% protein / 40% carbs / 30% fat
• Weight gain: 25% protein / 55% carbs / 20% fat
• Chronic illness support: 30% protein / 50% carbs / 20% fat
• Ketogenic therapy: 15% protein / 5% carbs / 80% fat
• Diabetes management: 25% protein / 35% carbs / 40% fat
• Longevity/mild restriction: 20% protein / 50% carbs / 30% fat

Once we know your target calories and the correct percentage split, we convert each macro to grams—using 4 kcal per gram for protein and carbs, and 9 kcal per gram for fat—and present both the absolute gram totals and their percentage of your overall intake. This dual approach ensures that whether you’re following a specific diet or focusing on a health goal, your macro targets are both accurate and tailored to your needs.

• Male Physiology: Ideal_kg = 50 + 2.3 × (height_in_inches − 60)
• Female Physiology: Ideal_kg = 45.5 + 2.3 × (height_in_inches − 60)
• Undisclosed Physiology: We average the male and female physiology calculations.
• Convert to pounds: Ideal_lbs = Ideal_kg × 2.20462

We estimate how many calories you burn from activities:

• Standing: burns more than sitting (MET ≈ 1.5)
• Walking: light walking burns more (MET ≈ 3.3)
• Jogging or running: burns even more (MET 7+)

MET = Metabolic Equivalent of Task. Learn more: MET Explained

We estimate how much water you need daily:

• Metric: 35 ml per kg of body weight
• Imperial: 0.5 fl oz per lb of body weight

Example: 70 kg → 2.45 liters/day. Learn more: Water Needs

We suggest how much sleep you need based on age:

• Newborns: 14–17 hrs
• Infants: 12–16 hrs
• Toddlers: 11–14 hrs
• Preschoolers: 10–13 hrs
• Children: 9–12 hrs
• Teens: 8–10 hrs
• Adults: 7+ hrs
• Older adults: 7–8 hrs

Learn more: Devine Formula

• Underweight: BMI < 18.5
• Normal: 18.5 ≤ BMI ≤ 24.9
• Overweight: 25 ≤ BMI ≤ 29.9
• Obesity: BMI ≥ 30