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HEALTH / SCREENING RATIO

Adult BMI Calculator

Calculate adult body mass index using your preferred weight and height units, then see the WHO reference classification with its limitations visible.

  • 01 Calculated in this tab
  • 02 Values stay in this browser tab
  • 03 Use boundary

Conversion input

Known value

Filter by unit name, symbol, or code. Your current selections remain available.

Preparing the calculator...

WEIGHT-TO-HEIGHT RATIO / ADULT SCREENING VIEW

See how one adult height turns into both a BMI result and a weight window

BMI becomes more useful when the ratio and its same-height weight window stay visible together. With the reviewed defaults ७० kg and १७० cm, the calculator converts height to 1.70 m, squares it to 2.89, returns BMI २४.२२, and places that result in the WHO adult Healthy weight band. At the same height, the healthy reference window on this page runs from ५३.५ kg to ७२ kg.

Worked default example

Entered adult measurements
Weight = ७० kg. Standing height = १७० cm.
Convert height to metres
१७० cm / 100 = 1.70 m.
Square the height
1.70 x 1.70 = 2.89.
Divide weight by height squared
७० kg / 2.89 = २४.२२.
Invert the same height for the healthy window
18.5 x 2.89 = ५३.५ kg, 24.9 x 2.89 = ७२ kg.
Returned page result
The calculator reports BMI २४.२२, WHO adult classification Healthy weight, and the same-height healthy reference window ५३.५ kg to ७२ kg.

What to enter and how to read the result

Enter a recent adult body weight and choose kilograms, pounds, or stone beside the field. Enter standing height without shoes and choose centimetres, metres, total inches, or decimal feet. The result panel then shows the BMI ratio first, followed by the WHO adult class, the lower and upper reference weights for the same height, and the height used in the calculation.

What the calculator actually does

Nirmion normalises the chosen units to kilograms and metres, applies BMI = weight / height^2, and then compares the ratio with the WHO adult reference bands. The same page also inverts the formula at your height with BMI 18.5 and 24.9 so the healthy reference weight window stays visible beside the main result.

Assumptions behind this page

The model assumes one recent body weight, one standing height, adult use only, and correct unit selection for each field. BMI is a screening ratio built from weight and height; it does not directly measure body-fat percentage, waist distribution, fitness, or disease risk in one individual.

Where this model stops helping

Do not use this adult BMI page as a diagnosis or treatment decision. Children and teenagers need age- and sex-specific growth references. Pregnancy, unusual muscularity, oedema, amputation, some ethnicity-related risk contexts, illness, and wider clinical context can all change how a BMI result should be interpreted.

HEIGHT-LOCKED VIEW

At one fixed height, BMI becomes a weight window. For १७० cm, the healthy reference range on this page is ५३.५ kg to ७२ kg.

Default BMI mapped onto the WHO adult bands

A horizontal BMI ruler with WHO adult bands from underweight through obesity class III, a marker at BMI २४.२२, and a note that the healthy-weight window at १७० cm runs from ५३.५ kg to ७२ kg.

Entered weight७० kg

Use a recent measured weight and switch units beside the field when needed.

Entered height१७० cm

The calculator converts this to 1.70 m before squaring it.

Returned BMI२४.२२

This reviewed default result lands in the WHO adult Healthy weight band.

Healthy window at this height५३.५ kg to ७२ kg

These are the page's BMI 18.5 and 24.9 inverse weights for the same १७० cm.

Default BMI mapped onto the WHO adult bands A horizontal BMI ruler with WHO adult bands from underweight through obesity class III, a marker at BMI २४.२२, and a note that the healthy-weight window at १७० cm runs from ५३.५ kg to ७२ kg. Underweight Healthy weight Overweight Obesity I Obesity II Obesity III Default BMI २४.२२ 15 18.5 25 30 35 40 42

Healthy window at १७० cm: ५३.५ kg to ७२ kg.

The visual makes the output reusable: the same default height produces both the BMI ratio and the inverse healthy-weight window shown in the result panel.

REVIEWED BMI SOURCE

Why the page uses WHO adult bands

The calculator definition cites the World Health Organization fact sheet on overweight and obesity, which includes adult BMI reference cutoffs. Nirmion uses those adult bands for a first screening view and keeps the limitations beside the result instead of presenting BMI as a diagnosis.

Read the WHO fact sheet on adult BMI, overweight, and obesity

BMI QUESTIONS

Adult BMI calculator FAQs

Does the BMI change if I switch from kilograms to pounds or from centimetres to inches?

No. The page first normalises the selected units to kilograms and metres, so equivalent inputs produce the same BMI २४.२२ and the same WHO adult classification.

Why does this BMI calculator show a reference weight range for my height?

The tool inverts the same BMI formula at your entered height using BMI 18.5 and 24.9. For the reviewed default height १७० cm, that produces ५३.५ kg to ७२ kg.

Can I use this page for teenagers, pregnancy, or athletic body composition?

No. This page is bounded to adults and BMI is only a screening ratio. Growth charts, pregnancy care, muscular build, oedema, amputation, and clinical context need different assessment models.