This adult BMI screening tool is intended for people age 20 and older. The formula uses weight and height only.
General estimate for planning only — not medical advice. Consult a doctor about your specific situation.
Calculation details
Adult screening estimate only, not a diagnosis. Body composition, age, pregnancy, medical history, and population-specific risk can change interpretation; discuss health decisions with a qualified clinician.
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What does this calculator estimate?
bmi calculator that computes body mass index from height and weight, with healthy ranges by age for men and women. Free, private, runs locally in your browser.
How this calculator works
Formula
BMI = 703 x weight (lb) / height (in)^2.
Worked example
170 lb at 5 ft 9 in: BMI 25.1, in the overweight band (25 to 29.9). Normal is 18.5 to 24.9.
Assumptions to verify
- Adult BMI ranges do not directly apply to children, pregnancy, athletes, or some medical contexts.
- BMI does not measure muscle, fat distribution, ethnicity-specific risk, or clinical history.
- Use this as a screening estimate and discuss health decisions with a qualified clinician.
Frequently asked questions
Is BMI a diagnosis?
No. BMI is a screening estimate. It can miss individual health context and body composition.
Who should be careful using BMI?
Children, pregnant people, athletes, and people with medical conditions should use clinical guidance rather than BMI alone.
Why does this adult BMI tool ask only for weight and height?
Adult BMI is calculated from weight relative to height. Age, sex, body composition, pregnancy, medical history, and population-specific risk still matter when interpreting the screening result.
Cite this tool
BoringToolsKit. “BMI Calculator.” boringtoolskit.com/bmi-calc/ (reviewed July 2026). Free to reference in articles, syllabi, and answer posts with a link.
Privacy: Inputs and results stay in this browser. Any future sponsored recommendation or advertisement will be clearly labeled and kept separate from the calculation.
How This Tool Works
Calculation Method
The tool applies the displayed formula or calculation logic to the values entered and returns a planning result.
Evidence basis
No unrelated authority link is added merely to make this page look sourced. Tool-specific external sources are shown only when they directly support the method, rate, or rule.
Assumptions to Verify
- These tools provide general estimates for planning and education only.
- They are not medical advice and not a substitute for a qualified healthcare professional.
- Always consult your doctor or another healthcare provider about your specific situation.
Privacy: The calculation runs in this browser. Shared links contain the page address only, not your inputs or results.