BMI Calculator – Free Body Mass Index Calculator 2025
Calculate your Body Mass Index instantly with our free bmi calculator. Works for adults in India and worldwide.
What is BMI Calculator?
A BMI calculator measures Body Mass Index, a simple number from your height and weight that estimates body fat. Our free tool helps you check if you are underweight, normal, overweight, or obese. Doctors worldwide use BMI as a first screening tool. It is fast, free, and works perfectly on mobile phones in India.
Body Mass Index was invented in the 1830s by Adolphe Quetelet. Today, WHO and Indian health organizations use it for population health studies. While BMI does not directly measure fat, it correlates well with health risks like diabetes and heart disease.
How BMI Calculator Works
Our tool uses the standard WHO formula. For metric: BMI = weight (kg) ÷ [height (m)]². For imperial: BMI = 703 × weight (lb) ÷ [height (in)]². You enter height and weight, the calculator converts units and calculates instantly in your browser – no data is saved or sent to servers.
BMI Formula Explained
Metric Formula: BMI = kg / (m × m)
Example: A person 65 kg, 1.70 m tall → 65 / (1.7 × 1.7) = 22.5 (Normal range)
Imperial Formula: BMI = 703 × lb / (in × in)
Example: 143 lb, 66.9 inches → 703×143/(66.9×66.9) = 22.5
BMI Categories for Indians and Asians
Standard WHO categories: Underweight below 18.5, Normal 18.5-24.9, Overweight 25-29.9, Obese 30 and above. However, Indian health experts often use lower cut-offs because Indians tend to have higher body fat at the same BMI compared to Europeans.
Indian Council of Medical Research suggests: Normal 18.5-22.9, Overweight 23-24.9, Obese 25+. Our bmi calculator shows WHO ranges by default, but consult your doctor for India-specific interpretation. This is especially important for people in Bangalore, Delhi, Mumbai managing lifestyle diseases.
Why Use This BMI Calculator
This bmi calculator is built for India – metric default (cm/kg), fast loading even on 4G, and privacy focused with no signup. Unlike mobile apps that track you, everything runs locally. Use it before starting gym, diet plans, or annual health checkups.
Combine it with our Age Calculator to track health by age, or Percentage Calculator for weight loss goals. For financial health, try EMI Calculator.
Limitations of BMI
BMI does not distinguish muscle from fat. Bodybuilders may show as overweight. It also does not account for age, sex, or fat distribution. Waist-to-hip ratio is better for abdominal obesity risk. Always use BMI as screening, not diagnosis. Pregnant women and children need different charts.
Learn more about BMI standards on WHO and Wikipedia. For Indian guidelines, check ICMR publications.
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Important Pages
FAQ
Is BMI accurate? BMI is a screening tool, not diagnosis. It does not measure muscle vs fat. Athletes may show high BMI but be healthy.
What is normal BMI in India? WHO says 18.5-24.9, but Indian guidelines suggest 18.5-22.9 as normal range.
Does it work for kids? No, children need age and sex based percentiles. Use pediatric growth charts instead.
Is my data saved? No, our bmi calculator runs locally in your browser. See Privacy Policy.
Is it free? Yes, 100% free like all TOOLVORA tools.