Everyday Tools
BMI Calculator
- Browser-based
- No signup
Enter height and weight in metric or US units to calculate BMI and see a general classification. This tool is for educational purposes only and is not medical advice.
Body mass index is a population screening metric, not a diagnosis of health or body composition. Athletes with high muscle mass and older adults with low muscle may fall outside typical categories despite being healthy for their context.
Use metric or US units consistently—mixing centimeters with pounds without conversion produces nonsense results. Consult a qualified professional for personal medical guidance rather than relying on BMI alone.
Pediatric BMI uses age- and sex-specific percentiles rather than adult cutoffs—this tool targets standard adult screening ranges only.
Waist circumference and body-fat percentage capture risk factors that BMI alone cannot—use them alongside this screening number.
100% Client-Side
Your data never leaves your computer.
How to use this tool
1. Select Metric or US units. 2. Enter weight and height (centimeters or feet and inches). 3. Click Calculate BMI. 4. Read the BMI value and general classification shown in the results.
Worked example
Example: 70 kg and 175 cm gives a BMI of about 22.9, in the normal weight range for adults.
When to use this
- General adult BMI screening from height and weight.
- Switching between metric and US units for the same person.
- Tracking BMI category when updating a wellness log.
- Teaching how weight and height combine into one index number.
Common examples
- 70 kg and 175 cm → BMI about 22.9 (normal adult screening range).
- 180 lb and 5 ft 10 in → BMI about 25.8 (borderline overweight category for adults).
- 65 kg and 160 cm → BMI about 25.4—useful when switching from imperial height inputs.
- 62 kg, 168 cm → BMI about 22.0 for metric wellness screening context.
- 200 lb, 5 ft 4 in → BMI about 34.3—compare with metric entry for same person.
What people search for
- bmi calculator
- body mass index calculator
- bmi calculator kg cm
- bmi calculator lbs feet
- calculate bmi online
Common mistakes
- Treating BMI as a diagnosis rather than a screening number.
- Entering height in centimeters when feet and inches mode is selected.
- Applying adult categories to children or athletes without context.
- Comparing BMI across different unit systems without converting first.
Related long-tail tasks
- estimate healthy weight range for height
- calculate body fat context with other metrics
- convert pounds to kg for BMI input
- track weight change percent over time
- plan calorie target after BMI screening
How it works
BMI is calculated as weight in kilograms divided by height in meters squared. US units are converted to metric before calculation. Classifications follow commonly used adult BMI ranges and are for general education only.
Limitations
BMI is a population-level screening metric, not a diagnosis. Athletes, children, and pregnant users need specialized measures.
Privacy and file handling
Your data is processed in your browser and is not uploaded to our server.
Accuracy & methodology
This section documents how the calculator works, what it leaves out, and when results were last reviewed. Figures are educational estimates—not professional advice—and are not labeled "current" unless tied to automatically updated reference data.
- Formula source or methodology
- BMI = weight (kg) ÷ height (m)². US units convert lb → kg and ft/in → meters before calculation. Classification uses WHO-style adult cut points: under 18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, 30+ obesity.
- Jurisdiction
- International (WHO adult categories)
- Unit system
- Metric (kg, cm) or US (lb, ft/in)
- Rounding method
- BMI rounds to one decimal place.
- Assumptions
- Adult height and weight snapshot
- Standard BMI formula; not pediatric BMI-for-age
- Known omissions
- Not medical advice. Does not diagnose, treat, or replace clinical assessment.
- Athletic/muscular builds, pregnancy, and ethnicity-specific ranges
- Children and teens (use child growth tool instead)
- Waist circumference or body composition
- Test cases (automated)
- 70 kg, 175 cm → BMI ≈ 22.9 (normal)
- Invalid height or weight returns an error
- Version & last verified
Logic version 1.0. Content and formulas last verified .
Important notice
This tool provides a general estimate for educational purposes and is not medical advice. Consult a qualified healthcare professional for personal guidance.
Specialized BMI Calculator guides
Explore focused guides for common searches—each page reuses this bmi calculator with different examples and FAQs.
Frequently asked questions
What units does the BMI calculator support?
You can use metric units (kilograms and centimeters) or US units (pounds and feet/inches).
Is BMI medical advice?
No. BMI is a general screening measure. This calculator is educational and does not provide medical advice.
How is BMI calculated?
BMI is weight in kilograms divided by height in meters squared. US inputs are converted to metric before calculation.
Part of these workflows
This tool is one step in a longer job. Jump straight to your step or open the full workflow guide.
Related tools
Related pages
- Track weight metrics — step-by-step workflow
- Browse all free online tools on Utilnivo
- Explore more everyday tools on Utilnivo
- Age Calculator — Calculate exact age in years, months, and days from a date of birth.
- Calorie Calculator — Estimate daily calorie needs from basic inputs.
- Unit Converter — Convert between common units of length, weight, volume, and temperature.
- Percentage Calculator — Calculate percentages, increases, decreases, and ratios.
- Pregnancy Due Date Calculator — Estimate a due date from the start of the last period.
Page last reviewed: