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BMI Calculator

Check your body mass index

Units

Your BMI

24.4

Category

Healthy Weight

Ideal

153 lbs

Range

129 lbs - 174 lbs

ft
in
lbs

Your BMI

24.4

Healthy Weight
1618.525303540
Ideal Weight

153 lbs

Healthy Range

129 lbs - 174 lbs

Great! You're at a healthy weight

Maintain your current lifestyle with balanced diet and regular exercise.

BMI Categories

Underweight
16 - 18.5
Healthy Weight
18.5 - 25
Overweight
25 - 30
Obese Class I
30 - 35
Obese Class II
35 - 40
Obese Class III
40 - 40+

About BMI

BMI is a screening tool, not a diagnostic measure. It doesn't account for muscle mass, bone density, age, or ethnicity. Consult a healthcare provider for personalized advice.

Frequently Asked Questions

Q

What is BMI?

Body Mass Index (BMI) is a screening tool that estimates body fat using your height and weight. Formula: BMI = weight (kg) / height (m)². For example, a person weighing 70 kg and 1.75 m tall has a BMI of 22.9 (70 ÷ 1.75² = 22.9), which falls in the healthy range.

  • Formula (metric): weight (kg) ÷ [height (m)]²
  • Formula (imperial): [weight (lbs) ÷ height (inches)²] × 703
  • Used by doctors worldwide as initial health screening
  • Takes 30 seconds to calculate with our tool

BMI was developed in the 1830s by Belgian mathematician Adolphe Quetlet. While not perfect, it's a quick, inexpensive way to screen for weight categories that may lead to health problems. The CDC and WHO use BMI as a standard health assessment tool.

Q

What is a healthy BMI range?

A healthy BMI ranges from 18.5 to 24.9 for adults. BMI under 18.5 indicates underweight, 25-29.9 is overweight, and 30+ is obese. For example, someone 5'9" should weigh between 125-169 lbs to maintain a healthy BMI.

  • Underweight (<18.5): Risk of malnutrition, osteoporosis, weakened immunity
  • Healthy (18.5-24.9): Lowest risk for weight-related disease
  • Overweight (25-29.9): Increased risk of heart disease and diabetes
  • Obese Class I (30-34.9): High risk — lifestyle changes recommended
  • Obese Class II-III (35+): Very high risk — medical consultation advised
BMI RangeCategoryHealth Risk
Below 18.5UnderweightIncreased
18.5 - 24.9Healthy WeightLow
25.0 - 29.9OverweightModerate
30.0 - 34.9Obese (Class I)High
35.0 - 39.9Obese (Class II)Very High
40.0+Obese (Class III)Extremely High

BMI categories are based on extensive research linking weight ranges to health outcomes. Higher BMI increases risk of heart disease, type 2 diabetes, high blood pressure, and certain cancers. According to the National Institutes of Health, maintaining a BMI in the healthy range can significantly reduce these risks.

Q

Is BMI accurate for everyone?

BMI is accurate for most adults but has limitations. It doesn't account for muscle mass, bone density, body composition, or age/sex differences. Athletes with high muscle mass may have "overweight" BMI but low body fat. Elderly people may have "healthy" BMI but insufficient muscle mass.

  • Not accurate for bodybuilders or athletes (high muscle mass)
  • May not reflect body fat in elderly (loss of muscle)
  • Doesn't distinguish between visceral and subcutaneous fat
  • Asian populations may have health risks at lower BMI (23+)
  • Children and teens need age-specific BMI percentiles

For example, a muscular athlete weighing 200 lbs at 5'10" has a BMI of 28.7 (technically "overweight"), but their body fat percentage might be just 10%. Conversely, an elderly person with low muscle mass could have a "healthy" BMI but high body fat. Use BMI as one tool alongside waist circumference, body fat percentage, and overall health markers.

Q

How do I calculate my BMI?

Calculate BMI by dividing weight in kilograms by height in meters squared. Metric example: 70 kg ÷ (1.75 m)² = 70 ÷ 3.06 = 22.9 BMI. Imperial example: (154 lbs ÷ 69 inches²) × 703 = (154 ÷ 4,761) × 703 = 22.7 BMI.

  • Step 1: Measure your weight (without clothes)
  • Step 2: Measure your height (without shoes)
  • Step 3: Use our calculator or apply formula
  • Step 4: Compare result to BMI categories above
  • Green zone (18.5-24.9): No action needed
  • Yellow zone (25-29.9): Consider lifestyle changes
Height120 lbs140 lbs160 lbs180 lbs200 lbs
5'2" (157 cm)21.925.629.332.936.6
5'4" (163 cm)20.624.027.530.934.3
5'7" (170 cm)18.821.925.128.231.3
5'10" (178 cm)17.220.123.025.828.7
6'0" (183 cm)16.319.021.724.427.1
6'2" (188 cm)15.418.020.523.125.7
Q

What BMI is considered overweight?

BMI of 25.0 to 29.9 is classified as overweight. For someone 5'9" tall, overweight means weighing 170-202 lbs. For 5'4", it's 146-174 lbs. Being overweight increases health risks moderately compared to healthy weight range (18.5-24.9).

  • Overweight is BMI 25.0-29.9 — a moderate health risk category
  • Losing 5-10% of body weight can significantly reduce health risks
  • Waist circumference adds context: >40 in (men) or >35 in (women) = higher risk
  • Asian populations may face increased risks at lower BMI thresholds (23+)
HeightHealthy WeightOverweight RangeObese (30+ BMI)
5'2" (157 cm)101-136 lbs137-163 lbs164+ lbs
5'4" (163 cm)108-145 lbs146-174 lbs175+ lbs
5'7" (170 cm)118-159 lbs160-191 lbs192+ lbs
5'9" (175 cm)125-168 lbs169-202 lbs203+ lbs
6'0" (183 cm)140-183 lbs184-220 lbs221+ lbs
6'2" (188 cm)148-193 lbs194-232 lbs233+ lbs

Example Calculations

1Healthy Weight Adult

Inputs

Weight154 lbs (70 kg)
Height5'9" (175 cm)

Result

BMI22.9
CategoryHealthy Weight
Healthy Range125-168 lbs
Ideal Weight (BMI 22)149 lbs (68 kg)

BMI = 70 / (1.75)² = 70 / 3.0625 = 22.9. This falls in the healthy range (18.5-24.9). Healthy weight range for 5'9": 18.5 × 1.75² = 56.7 kg (125 lbs) to 24.9 × 1.75² = 76.2 kg (168 lbs). Ideal weight at BMI 22: 22 × 3.0625 = 67.4 kg (149 lbs).

2Overweight Example

Inputs

Weight190 lbs (86 kg)
Height5'9" (175 cm)

Result

BMI28.1
CategoryOverweight
To Reach Healthy BMILose 22 lbs
Healthy Range125-168 lbs

BMI = 86 / (1.75)² = 86 / 3.0625 = 28.1. This is in the overweight range (25-29.9). To reach BMI 24.9: 24.9 × 3.0625 = 76.3 kg (168 lbs). Weight to lose: 86 - 76.3 = 9.7 kg (22 lbs). Healthy range: 125-168 lbs.

3Metric Calculation

Inputs

Weight65 kg
Height1.70 m

Result

BMI22.5
CategoryHealthy Weight
Calculation65 ÷ (1.70)² = 22.5
Healthy Range53-72 kg

BMI = 65 / (1.70)² = 65 / 2.89 = 22.5. Healthy range for 1.70m: 18.5 × 2.89 = 53.5 kg to 24.9 × 2.89 = 72.0 kg. Ideal weight (BMI 22): 22 × 2.89 = 63.6 kg.

Formulas Used

BMI Formula (Metric)

BMI = weight (kg) / height (m)²

Standard metric formula used worldwide.

Where:

weight= Body weight in kilograms
height= Height in meters

BMI Formula (Imperial)

BMI = [weight (lbs) / height (in)²] × 703

Imperial formula with conversion factor.

Where:

703= Conversion factor for imperial units

Understanding BMI

Body Mass Index (BMI) is a simple calculation using height and weight to estimate body fat. The formula divides your weight in kilograms by your height in meters squared (kg/m²). For imperial units, divide weight in pounds by height in inches squared, then multiply by 703.

While not perfect, BMI is a useful screening tool for identifying potential weight problems. The World Health Organization (WHO) and CDC use BMI categories — underweight (below 18.5), healthy weight (18.5-24.9), overweight (25-29.9), and obese (30+) — as initial indicators of health risk.

For a more complete picture of body composition, combine BMI with waist circumference measurement and body fat percentage testing. Athletes and muscular individuals should rely on body fat percentage rather than BMI alone, since muscle weighs more than fat and can produce misleadingly high BMI readings.

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Last Updated: Mar 11, 2026

This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.

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