BMR & BMI Calculator

BMR Calculator Overview The Basal Metabolic Rate (BMR) is the amount of energy your body uses at rest in a neutral environment, essentially the “idle mode” of your metabolism. Imagine it like a parked car idling—your body still consumes energy to keep vital systems functioning, like your heart, brain, and organs. BMR is measured under conditions like after 12 hours of fasting, when your body is at its most relaxed state.

Choose Units:

• US Units
• Metric Units

Input Your Details:

• Age: 28 (age range: 15 – 80)
• Gender: Male/Female
• Height: 5 feet 10 inches
• Weight: 160 pounds

Result:

• BMR = 1,702 Calories/day

Daily Calorie Needs Based on Activity Level:

Activity Levels Explained:

• Exercise (15-30 min of elevated heart rate activity)
• Intense exercise (45-120 min of elevated heart rate activity)
• Very intense exercise (2+ hours of elevated heart rate activity)

Related Calculators

Body Fat Calculator

Calorie Calculator

Understanding BMR in Simple Terms
BMR represents the number of calories your body needs just to stay alive—breathing, sleeping, and maintaining organs like the heart and brain. Around 70% of the calories you burn every day goes towards these basic functions. Physical activity and digestion account for the rest of your daily energy expenditure.

Calculation Methods

• Mifflin-St Jeor Equation (Most Accurate)
  • For Men: BMR = 10W + 6.25H - 5A + 5
  • For Women: BMR = 10W + 6.25H - 5A - 161
• Revised Harris-Benedict Equation
  • For Men: BMR = 13.397W + 4.799H - 5.677A + 88.362
  • For Women: BMR = 9.247W + 3.098H - 4.330A + 447.593
• Katch-McArdle Formula (Best for those who know their body fat percentage)
  • BMR = 370 + 21.6(1 - F)W

Where:

• W = Weight in kg
• H = Height in cm
• A = Age
• F = Body fat percentage

Factors that Impact Your BMR

1. Muscle Mass: More muscle = higher BMR.
2. Age: As you age, BMR tends to decrease.
3. Genetics: Hereditary traits play a role.
4. Environment: Cold weather increases BMR.
5. Diet: Smaller frequent meals can increase BMR.
6. Pregnancy & Supplements: Pregnancy increases BMR; some supplements also boost it.

BMR Tests

Online BMR calculators are a great tool to estimate your needs, but for a precise reading, consult a professional with tools like calorimetry devices found in health centers.

BMI Calculator
Enter Your Details Below:

Choose Units:

• US Units
• Metric Units

Input Your Details:

• Age: 25 (age range: 2 – 120)
• Gender: Male/Female
• Height: 180 cm
• Weight: 65 kg

Result:

• BMI = 20.1 kg/m² (Normal)

Healthy BMI Range: 18.5 kg/m² – 25 kg/m²
Healthy Weight Range for Your Height: 59.9 kg – 81 kg
BMI Prime: 0.8
Ponderal Index: 11.1 kg/m³

Understanding BMI

BMI helps determine if your weight is within a healthy range for your height. It categorizes you as underweight, normal, overweight, or obese.

BMI Categories for Adults (WHO Standard): | Classification | BMI Range (kg/m²) | |———————–|————————| | Severe Thinness | < 16 | | Moderate Thinness | 16 - 17 | | Mild Thinness | 17 - 18.5 | | Normal | 18.5 - 25 | | Overweight | 25 - 30 | | Obese Class I | 30 - 35 | | Obese Class II | 35 - 40 | | Obese Class III | > 40 |

BMI for Children & Teens

BMI categories vary by age and gender for those aged 2-20. Check the CDC BMI growth charts for a clearer picture.

Risks Related to BMI

• Overweight Risks: High blood pressure, cholesterol, diabetes, heart disease, certain cancers, and more.
• Underweight Risks: Malnutrition, osteoporosis, decreased immune function, growth issues.

Limitations of BMI: While BMI is a helpful indicator, it does not directly assess body fat or muscle mass. Athletes and muscular individuals may have high BMIs but be very healthy.

BMI Prime

BMI Prime is the ratio of your BMI to the upper limit considered healthy (25 kg/m²). It’s a simple way to see how much above or below the healthy weight range you are.

• Underweight: BMI Prime < 0.74
• Normal: BMI Prime = 0.74 – 1
• Overweight: BMI Prime > 1

Ponderal Index

The Ponderal Index is similar to BMI but more accurate for very tall or very short individuals. It’s calculated by cubing your height rather than squaring it.