BMI Calculator: Free Body Mass Index Calculator for Men & Women (by Age & Height)
Use this clinical BMI calculator to calculate your Body Mass Index, healthy weight range, BMI Prime, and New Oxford BMI using standard US units (feet, inches, and pounds) or metric units (centimeters and kilograms). Built for adult men and women ages 20 and older, this tool compares your score against official CDC, NIH (NHLBI), and WHO weight categories—plus advanced adjustments for tall/short stature and muscular builds.
Your Profile
Body Mass Index (BMI) Assessment Report
CDC & WHO Adult BMI Formula Evaluation
Source: healthcalc.app
User Input Parameters
Calculated Results & Metrics
Clinical Guidance & Summary Insights
- Calculated Body Mass Index of 23.0 kg/m² falls into the Healthy Weight (Normal) CDC category.
- Healthy adult BMI range according to CDC guidelines is 18.5 – 24.9 kg/m².
- Your healthy weight range for your height is 128.9 to 173.5 lb.
BMI Result
Your Result
Your BMI is
128.9 – 173.5 lb
for your height (BMI 18.5–24.9)
0.92
Ratio to BMI 25 (0.74–1.00 is optimal)
12.9 kg/m³
Normal adult range: 11.0–15.0 kg/m³
Waist Risk & Body Composition Analysis
Target waist under half your height (35.0 in).
NHLBI cutoff is 40 inches for adult men.
BMI Category Table (WHO)
| Category | BMI Range (kg/m²) | Risk Level |
|---|---|---|
| Severe Thinness | < 16.0 | Very High |
| Moderate Thinness | 16.0 – 16.9 | High |
| Mild Thinness | 17.0 – 18.4 | Moderate |
| Normal | 18.5 – 24.9 | Low |
| Overweight | 25.0 – 29.9 | Moderate |
| Obesity Class I | 30.0 – 34.9 | High |
| Obesity Class II | 35.0 – 39.9 | Very High |
| Obesity Class III | ≥ 40.0 | Extreme |
BMI Chart for Men by Height and Weight
This BMI chart for men by height and weight plots adult CDC categories (underweight, healthy weight, overweight, and obesity) using the standard BMI formula: BMI = 703 × weight (lb) ÷ height (in)² (US) or BMI = weight (kg) ÷ height (m)² (Metric).
Target Healthy Weight
GoalBased on your height, your ideal healthy weight range (BMI 18.5 - 24.9) is between 128.9 lbs and 173.5 lbs.
BMI Prime
Advanced MetricBMI Prime is a ratio of your BMI to the maximum healthy limit (BMI 25). A value between 0.74 and 1.0 is considered optimal.
Your BMI Prime
Ponderal Index (PI)
Advanced MetricUnlike BMI which uses height squared, PI uses height cubed (kg/m³). This makes it more accurate for very tall or very short people.
Your Ponderal Index
New BMI (Oxford)
Advanced MetricThe "New BMI" formula (1.3 × weight in kg ÷ height in m2.5) was designed by Oxford mathematicians to provide a fairer, more accurate reading for very tall or short individuals.
Your New BMI
US National Stats
ComparisonThe average BMI for US males in the Adults (20-39) age group is roughly 28.3.
Difference
Next-Step Clinical & Metabolic Actions
Optimal Healthy Weight Range (BMI 23.0 kg/m²)
Great job! Your BMI of 23.0 kg/m² is squarely within the CDC and WHO healthy adult bracket (18.5–24.9 kg/m²). Maintain your current weight with balanced macronutrients, regular strength and cardiovascular training, and a waist-to-height ratio under 0.50.
Medical Disclaimer: This calculator provides clinical screening estimates based on CDC, NIH (NHLBI), and WHO adult equations and is not a substitute for professional medical diagnosis.
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Adult BMI Categories Chart (CDC & WHO Standards)
The Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) use standard BMI thresholds for all adults age 20 and older. Below is how each category maps to health risk, along with exact weight equivalents for an average 5 ft 4 in (64-inch) woman and 5 ft 10 in (70-inch) man:
| BMI Category | BMI Range (kg/m²) | Weight at 5'4" (Women Avg) | Weight at 5'10" (Men Avg) | Cardiometabolic Risk Level |
|---|---|---|---|---|
| Severe Thinness | Below 16.0 | Under 93 lbs | Under 112 lbs | Very High (Nutritional deficiency risk) |
| Moderate to Mild Underweight | 16.0 – 18.4 | 93 – 107 lbs | 112 – 128 lbs | Moderate (Bone density & immune risk) |
| Healthy Weight (Normal) | 18.5 – 24.9 | 108 – 145 lbs | 129 – 174 lbs | Low (Optimal baseline range) |
| Overweight | 25.0 – 29.9 | 146 – 174 lbs | 175 – 208 lbs | Moderate (Check waist size & body fat %) |
| Obesity Class I | 30.0 – 34.9 | 175 – 203 lbs | 209 – 243 lbs | High |
| Obesity Class II | 35.0 – 39.9 | 204 – 232 lbs | 244 – 278 lbs | Very High |
| Obesity Class III (Severe) | 40.0 or higher | 233+ lbs | 279+ lbs | Extremely High |
Healthy Weight Range by Height Chart (US Pounds & Kilograms)
Looking for what you should weigh for your exact height? This reference table calculates the official healthy BMI bracket (18.5 to 24.9) alongside the overweight threshold (25.0 to 29.9) for heights from 5 ft 0 in to 6 ft 4 in.
| Height (ft / in) | Height (cm) | Healthy Weight Range (BMI 18.5–24.9) | Overweight Range (BMI 25.0–29.9) | Obesity Threshold (BMI ≥ 30.0) |
|---|---|---|---|---|
| 5 ft 0 in (60") | 152.4 cm | 95 – 127 lbs (43 – 58 kg) | 128 – 153 lbs | 154+ lbs (70+ kg) |
| 5 ft 2 in (62") | 157.5 cm | 101 – 136 lbs (46 – 62 kg) | 137 – 163 lbs | 164+ lbs (74+ kg) |
| 5 ft 4 in (64") | 162.6 cm | 108 – 145 lbs (49 – 66 kg) | 146 – 174 lbs | 175+ lbs (79+ kg) |
| 5 ft 6 in (66") | 167.6 cm | 115 – 154 lbs (52 – 70 kg) | 155 – 185 lbs | 186+ lbs (84+ kg) |
| 5 ft 8 in (68") | 172.7 cm | 122 – 164 lbs (55 – 74 kg) | 165 – 196 lbs | 197+ lbs (89+ kg) |
| 5 ft 10 in (70") | 177.8 cm | 129 – 174 lbs (58 – 79 kg) | 175 – 208 lbs | 209+ lbs (95+ kg) |
| 6 ft 0 in (72") | 182.9 cm | 136 – 184 lbs (62 – 83 kg) | 185 – 220 lbs | 221+ lbs (100+ kg) |
| 6 ft 2 in (74") | 188.0 cm | 144 – 194 lbs (65 – 88 kg) | 195 – 233 lbs | 234+ lbs (106+ kg) |
| 6 ft 4 in (76") | 193.0 cm | 152 – 205 lbs (69 – 93 kg) | 206 – 246 lbs | 247+ lbs (112+ kg) |
How BMI Differs by Sex, Age, and Muscle Mass
Although the mathematical BMI equation is identical for everyone age 20 and older, a single number means very different things depending on your biology and training habits:
1. BMI for Men vs. Women
At the exact same BMI, adult women naturally carry 8% to 11% more essential body fat than adult men due to hormonal and reproductive physiology. Conversely, men tend to store excess weight as visceral fat (deep abdominal fat surrounding organs), whereas pre-menopausal women more commonly store subcutaneous fat around the hips and thighs.
- Male Waist Risk Cutoff (NHLBI): Above 40 inches (102 cm) significantly elevates cardiovascular and metabolic risk, even if BMI is under 30.
- Female Waist Risk Cutoff (NHLBI): Above 35 inches (88 cm) signals elevated visceral fat risk.
2. Athletic BMI: Why Lifters & Athletes Score “Overweight”
Skeletal muscle is dense and heavy. A 5 ft 10 in man who weighs 195 lbs with 12% body fat has a BMI of 28.0 (“Overweight”), despite having elite cardiovascular and metabolic health. If you lift weights three or more days per week or play competitive sports:
- Check your Waist-to-Height Ratio (WHtR): Keep your waist measurement under half your height in inches (WHtR < 0.50).
- Pair your result with our U.S. Navy Body Fat Calculator to separate lean muscle mass from fat tissue.
3. Age-Related BMI Shifts (Adults Over 50 & Seniors)
After age 40, adults naturally lose 3% to 8% of muscle mass per decade (sarcopenia). Because muscle is replaced by lighter fat tissue, an older adult can maintain a “normal” BMI of 23.5 while actually carrying excess visceral fat (“skinny fat” or normal-weight obesity). On the other hand, clinical geriatrics research shows that adults over age 65 often experience better longevity and bone protection with a slightly higher BMI between 23.0 and 27.0 compared to being near the 18.5 underweight border.
4. Ethnic & Racial Cutoffs (Asian American Guidelines)
Clinical research from the WHO and American Diabetes Association shows that Asian and South Asian adults develop type 2 diabetes and hypertension at lower BMI levels. For Asian American adults, clinical screening thresholds are typically adjusted to:
- Healthy BMI: 18.5 to 22.9 kg/m²
- Overweight: 23.0 to 27.4 kg/m²
- Obesity: 27.5 kg/m² or higher
How to Calculate BMI: Step-by-Step US & Metric Formulas
Our calculator computes four distinct clinical biometrics simultaneously so you are not relying on a single 19th-century equation:
How to Calculate BMI in Pounds and Inches (3-Step US Standard Method)
Because US scales measure weight in pounds and height in feet and inches, the CDC uses a conversion factor of 703 to match the standard kg/m² scale. Use this exact formula: BMI = 703 × Weight (lbs) ÷ [Height (in)]²
- Convert your height to total inches and square it: Multiply your height in feet by 12 and add your remaining inches (for example, 5 ft 8 in = (5 × 12) + 8 = 68 inches). Multiply that number by itself: 68 × 68 = 4,624.
- Divide your weight in pounds by your squared height: Divide your scale weight in lbs by the number from Step 1 (for a 160 lb adult: 160 ÷ 4,624 = 0.034602).
- Multiply by 703: Multiply that decimal by 703 to get your final US BMI score (0.034602 × 703 = 24.3 kg/m², which falls in the CDC Healthy Weight range).
1. Standard CDC / WHO BMI Formula
- US Imperial Formula:
BMI = 703 × Weight (lb) ÷ [Height (in)]² - Metric Formula:
BMI = Weight (kg) ÷ [Height (m)]² - Worked Example: A person standing 5 ft 10 in (70 inches) and weighing 170 lbs has a height squared of
70 × 70 = 4,900. Dividing170 ÷ 4,900 = 0.03469, then multiplying by703gives a BMI of 24.4 kg/m² (Healthy Weight).
2. New Oxford BMI Formula (For Tall & Short Adults)
Proposed by Nick Trefethen, Professor of Numerical Analysis at Oxford University, the traditional height-squared denominator penalizes tall people (making them look overweight when lean) and flatters short people. The New BMI uses an exponent of 2.5:
- Formula:
New BMI = 1.3 × Weight (kg) ÷ [Height (m)]2.5 - If you are shorter than 5 ft 2 in or taller than 6 ft 1 in, rely on your New Oxford BMI and Ponderal Index output in the results card above.
3. BMI Prime & Ponderal Index (PI)
- BMI Prime: Divides your BMI by the upper healthy cutoff of 25.0 (
BMI Prime = BMI ÷ 25). A score of 0.74 to 1.00 is optimal. A score of 1.08 means you are exactly 8% above the healthy weight threshold. - Ponderal Index (Corpulence Index): Uses height cubed (
kg / m³) to evaluate leanness across extreme height variations. A normal adult Ponderal Index ranges from 11.0 to 15.0 kg/m³.
Frequently Asked Questions (FAQs)
What is a good BMI for my age and height?
For adults aged 20 to 64, a good BMI is between 18.5 and 24.9 kg/m², regardless of height. For adults aged 65 and older, many clinicians consider a BMI between 23.0 and 27.0 protective against frailty and bone loss.
Is the BMI calculation different for men and women?
The mathematical formula is identical for men and women, which is one of BMI's main limitations. Because men carry more muscle mass and women naturally have higher essential body fat, you should always cross-check your BMI with sex-specific waist thresholds (under 40 inches for men; under 35 inches for women).
Why does the BMI calculator say I am overweight when I lift weights?
BMI only knows your total scale weight—it cannot distinguish between 20 pounds of skeletal muscle and 20 pounds of adipose fat. Muscular athletes and lifters frequently register a BMI between 25.5 and 29.0 while maintaining 10% to 15% body fat. Use our Body Fat Calculator or check that your waist is less than half your height.
How much weight do I need to lose to drop 1 BMI point?
For an average adult between 5 ft 4 in and 5 ft 10 in, losing 1 BMI point requires losing roughly 6 to 7 pounds (2.7 to 3.2 kg). You can see your exact pound target in the "Target Healthy Weight" card inside the calculator results.
Can I use this BMI calculator for teens or children under 20?
No. Children and teenagers (ages 2 to 19) grow at varying rates, so their BMI must be evaluated using CDC age- and sex-specific growth percentiles rather than fixed adult cutoffs.
How do I calculate my BMI manually in pounds and feet?
First, convert your height in feet and inches into total inches (for example, 5 feet 6 inches is 66 inches) and multiply it by itself (66 × 66 = 4,356). Next, divide your weight in pounds by that squared height, and multiply the result by 703. For a 150 lb adult at 5'6", the math is (150 ÷ 4,356) × 703 = 24.2 kg/m² (Healthy Weight).
Why do you multiply by 703 when calculating BMI in US units?
Body Mass Index was originally designed using the metric system (kilograms per square meter, or kg/m²). The number 703 is the exact mathematical conversion factor required to convert pounds per square inch (lb/in²) into kilograms per square meter (kg/m²) without having to manually convert your weight to kilos or height to meters first.
Clinical Methodology & Medical Sources
Written by the Free USA Calculators Clinical Editorial Team and clinically reviewed for accuracy against official United States federal health guidelines. Last updated on November 7, 2026.
Official Clinical Citations:
- Centers for Disease Control and Prevention (CDC): Adult BMI Categories — Standard US adult BMI screening thresholds (18.5–24.9 healthy range, 25.0–29.9 overweight, 30.0+ obesity).
- National Heart, Lung, and Blood Institute (NIH / NHLBI): Assessing Your Weight & Waist Circumference Risk — Sex-specific abdominal waist circumference cutoffs (>40 inches for men; >35 inches for women).
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Explore fast, mobile-first visual stories on BMI, Calorie Deficit, TDEE, Macros, Sleep Cycles, and Healthy Habits.
Evidence-Based Clinical Formulations
All biometrics, body composition, and caloric computations adhere to the Mifflin-St Jeor, Harris-Benedict, and U.S. Navy standards referenced by the Centers for Disease Control and Prevention.
Cardiovascular & Nutrition Tips
Target heart rates, daily sodium ceilings, and macronutrient distributions align with the American Heart Association (AHA) and USDA Dietary Guidelines for Americans.
Practical Health Takeaways
Pair your calculation with structured sleep (7-9 hrs), balanced hydration (half body weight in oz), and a 500 kcal sustainable deficit for healthy body composition management.