BMI Calculator 2026: Calculate Your Body Mass Index Instantly

Wondering if your weight is healthy for your height? Our free BMI calculator gives you an instant result in pounds and inches — no metric conversion needed — along with your CDC weight category.

👉 Calculate your BMI free on Kalkulo

What Is BMI?

Body Mass Index (BMI) is a number calculated from your weight and height that gives a rough indication of whether you're at a healthy weight. Developed in the 19th century and adopted by the CDC and WHO, it remains the most widely used screening tool for weight categories in adults.

How to Calculate BMI in Pounds and Inches

The US formula uses imperial measurements:

BMI = (Weight in lbs × 703) ÷ Height in inches²

For example, a person weighing 154 lbs at 5'9" (69 inches): BMI = (154 × 703) ÷ (69 × 69) = 108,262 ÷ 4,761 = 22.7

Skip the math — use our free BMI Calculator instead.

CDC BMI Categories for Adults

BMI	Weight Category
Below 18.5	Underweight
18.5 – 24.9	Healthy Weight ✅
25.0 – 29.9	Overweight
30.0 – 34.9	Obesity Class I
35.0 – 39.9	Obesity Class II
40.0 and above	Obesity Class III (Severe)

Healthy Weight Ranges by Height (US)

Height	Healthy Weight (BMI 18.5–24.9)	Overweight (BMI 25–29.9)
5'4"	108 – 145 lbs	145 – 174 lbs
5'7"	118 – 159 lbs	159 – 191 lbs
5'10"	129 – 174 lbs	174 – 209 lbs
6'0"	140 – 188 lbs	188 – 226 lbs

BMI Limitations: What the Number Doesn't Tell You

BMI is a useful starting point but has well-known limitations:

Athletes and bodybuilders: High muscle mass can push BMI into the overweight range despite low body fat
Older adults: BMI may underestimate body fat as muscle mass decreases with age
Ethnic differences: The CDC acknowledges that health risks associated with BMI can vary by ethnicity
Children: BMI is calculated differently for those under 18 using age- and sex-specific percentile charts

BMI and Health in the United States

According to the CDC, more than 73% of American adults are overweight or obese — one of the highest rates in the world. Elevated BMI is linked to increased risk of type 2 diabetes, heart disease, stroke, and certain cancers. If your BMI falls outside the healthy range, speak to your doctor about next steps.

Tips to Reach a Healthy BMI

Follow the Dietary Guidelines for Americans (MyPlate recommendations)
Aim for at least 150 minutes of moderate aerobic activity per week
Incorporate strength training twice a week to build and maintain muscle
Work with a registered dietitian (RD) for a personalised nutrition plan

👉 Calculate your BMI free on Kalkulo

Disclaimer: BMI is a screening tool, not a diagnostic measure. It does not directly measure body fat. Always consult a healthcare provider for a full health assessment.