Skip to content
HealtyFoood

Free Tool

BMI Calculator

Calculate your Body Mass Index and understand what your result means. Includes BMI categories, limitations, and practical next steps.

Your Details

BMI Categories (Adults)

Below 18.5Underweight
18.5 – 24.9Normal Weight
25.0 – 29.9Overweight
30.0 – 34.9Obese (Class I)
35.0 – 39.9Obese (Class II)
40.0 and aboveSeverely Obese (Class III)

Frequently Asked Questions

What is BMI?

BMI (Body Mass Index) is a numerical value calculated from height and weight that is widely used as a screening tool for weight categories — underweight, normal, overweight, and obese. Formula: BMI = weight (kg) ÷ height² (m²). A BMI between 18.5 and 24.9 is considered normal weight for adults.

What are the BMI categories?

Standard adult BMI categories: Underweight = below 18.5, Normal Weight = 18.5–24.9, Overweight = 25.0–29.9, Obese Class I = 30.0–34.9, Obese Class II = 35.0–39.9, Obese Class III = 40.0 and above. These categories are the same for men and women but different scales are used for children.

Is BMI an accurate measure of health?

BMI is a useful population-level screening tool but has significant limitations at the individual level. It does not account for muscle mass (athletes can have high BMIs despite low body fat), bone density, age-related fat distribution, or ethnic differences in health risks at different BMI levels. Use it as a starting point, not a definitive health measure.

Can you have a normal BMI but still be unhealthy?

Yes — this is called 'metabolically obese normal weight' or MONW. People with normal BMIs can still have high visceral fat (fat around organs), poor metabolic markers, and elevated cardiovascular risk. Body fat percentage and waist circumference are better predictors of metabolic health than BMI alone.

How do I lower my BMI?

BMI decreases when you lose body fat or, in cases of underweight, gain healthy muscle mass. The most effective approach: create a moderate calorie deficit (300–500 kcal/day), prioritize high-protein foods to preserve muscle, do resistance training to maintain lean mass, and be consistent for 8–16 weeks.

Related Calculators

Macro Calculator →Calorie Calculator →Body Fat Calculator →Protein Calculator →Water Intake Calculator →

Improve Your BMI

Browse Healthy Recipes to Reach a Healthy BMI

Free recipes with full nutrition facts and practical guides to help you move into the healthy BMI range — no sign-up required.

Browse Free Recipes

Method: Weight (kg) ÷ height (m)², with World Health Organization category thresholds. See full methodology and limitations. Estimates for general education, not medical advice.