BMI calculator

BMI calculator defaults to Metric, where Weight means kilograms and Height means centimetres. Imperial mode expects pounds and inches. The labels do not change beside the numeric fields, so the selected Units menu is the only indication of measurement system. Confirm it before calculating and do not mix kilograms with inches or pounds with centimetres.

Metric BMI equals kilograms divided by height in metres squared. The implementation converts centimetres to metres by dividing Height by 100. Imperial BMI equals 703 multiplied by pounds, divided by inches squared. The factor 703 adapts the pound-and-inch inputs to the conventional BMI scale.

Convert measurements before entry if your source uses stones, feet plus inches, or metres. Six feet is 72 inches, not 6. A height of 1.75 metres is 175 centimetres. Keep enough precision during conversion and round only the displayed BMI unless a professional workflow states another method.

Enter 70 for Weight and 175 for Height in Metric mode. Height becomes 1.75 metres. Squaring 1.75 gives 3.0625, and 70 divided by 3.0625 is about 22.857. The page displays BMI: 22.9 because it rounds to one decimal place.

A BMI of 22.9 falls below 25 and not below 18.5, so the output category is Healthy range. The calculation uses the unrounded BMI for classification before displaying one decimal. A value close to a threshold can therefore display as 25.0 while being classified from a slightly lower or higher underlying value.

Recheck the source measurements when the result is unexpected. A centimetre value entered as metres, such as 1.75 instead of 175, makes the denominator extremely small and produces a huge value. A weight entered in pounds while Metric is selected also changes the result substantially.

Select Imperial and enter 154 pounds and 69 inches. The formula calculates 703 times 154 divided by 69 squared. The result is about 22.739, which displays as 22.7 and falls in Healthy range under the implemented adult bands.

Convert feet and inches into total inches before entry. Five feet nine inches equals 5 times 12 plus 9, or 69 inches. Entering 5.9 does not represent that height. If a scale reports stones and pounds, convert the complete weight to pounds first.

The page does not preserve a result when Reset is pressed. Reset also returns the Units selector to Metric. If you run several imperial examples, confirm the mode after each reset rather than assuming the previous choice remains active.

The workbench labels BMI below 18.5 Underweight. Values from 18.5 up to but not including 25 receive Healthy range. Values from 25 up to but not including 30 receive Overweight. Values at 30 or above receive Obesity range. These comparisons use the unrounded computed value.

The labels are broad adult screening categories. They do not account for age, sex, pregnancy, muscle mass, body composition, ethnicity-related risk patterns, disability, or clinical history. BMI does not diagnose a condition or determine an individual treatment target.

Children and adolescents require age- and sex-specific growth references rather than these fixed adult bands. Athletes and people with unusual body composition can also receive a result that needs professional interpretation. Use the number as a general screening measure and discuss concerns with a qualified health professional.

Height should be measured without shoes on a level surface, and weight should come from a scale used consistently. Clothing, time of day, hydration, equipment, and posture can change inputs. The calculator cannot distinguish measurement variation from a meaningful body change.

For tracking, use the same units and a consistent measurement routine. Record the raw height and weight with the BMI rather than storing only the rounded index. That lets you reproduce the calculation and correct a transcription error later.

Do not add false precision. A height estimated to the nearest several centimetres does not support interpreting tiny changes in BMI. The page displays one decimal because that is its formatting rule, not because every input is accurate to that level.

The shared number parser checks only that entered values convert to finite numbers. It does not require positive weight or height. Zero height can lead to an infinite BMI, negative weight can produce a negative BMI, and negative height is squared. Those outputs are mathematical artifacts, not health results.

Enter positive measurements in the selected units. If the page shows Infinity, an impossible category, or a negative number, inspect both fields and mode immediately. Blank numeric fields can convert to zero, so explicitly fill both values instead of relying on required-field validation.

The page does not set minimum or maximum plausible measurements. It also does not warn about decimal separators unsupported by the browser's number input. Use standard numeric entry accepted by the field and verify the values shown before copying the result.

BMI relates mass to height and can support population summaries or an initial adult screening discussion. It does not directly measure body fat, fat distribution, metabolic health, fitness, nutrition, or disease. Two people with the same BMI can have different clinical circumstances.

Do not change medication, diet, exercise, or care based only on this page. Symptoms, rapid weight change, eating concerns, pregnancy, or pediatric growth questions need appropriate professional assessment. The result panel itself states that BMI is a general screening measure, not a diagnosis.

Category language can be sensitive. When sharing a result, include context and avoid treating a label as a judgment about a person. In research or reporting, state the formula, unit system, thresholds, measurement source, and limitations.

Percentage calculator can compare a weight change with a prior value, but it does not interpret health. Age calculator supplies calendar age, which may be needed for an age-specific clinical reference that this BMI page lacks. Neither replaces a clinical assessment.

Use unit-conversion tools or verified conversion factors before BMI when measurements arrive in unsupported units. Do not use Discount, VAT, loan, or interest pages for health quantities merely because they accept numbers. Their labels and formulas model unrelated contexts.

For an adult screening check, choose units, enter positive measurements, calculate, verify the formula, and retain the raw inputs. If the result sits near a threshold or affects a decision, ask a qualified professional to interpret it with the person's broader information.

Category selection happens before one-decimal formatting. A computed BMI of 24.96 displays as 25.0 but remains Healthy range because the unrounded value is below 25. A computed 25.01 also displays as 25.0 but receives Overweight. The rounded number alone cannot explain a boundary label.

Retain height and weight when a threshold matters, and reproduce the full calculation rather than recategorizing the displayed one-decimal value. Small measurement changes can move an unrounded result across a boundary. That movement does not by itself establish a clinical change.

Do not choose a desired category and adjust measurements or rounding to reach it. Use measured inputs and treat threshold proximity as a reason for cautious interpretation, not greater certainty.

For repeated checks, record date, unit system, weight, height, equipment, and relevant measurement conditions. Adult height is often treated as stable, but a mistaken or rounded height affects every later BMI. Use the same verified height unless a new measurement is warranted.

Short-term weight fluctuation can reflect water, food, clothing, or scale variation. A one-decimal BMI change may not represent a meaningful health change. Review trends over an appropriate period with professional context when needed.

BMI should not become the only outcome in a health plan. Clinical history, symptoms, laboratory findings, function, nutrition, and other measures may matter. This page cannot collect or interpret them.

Privacy also matters. Height and weight can be sensitive personal information. The calculation runs in the browser and PWRKIT does not send entered values to its processing server, but users must still follow device, workplace, and record-handling rules.

If sharing a trend, avoid exposing raw measurements beyond the intended audience. Use secure clinical or organizational systems when they are required instead of copying results into an informal channel.

A manual metric check squares height in metres before division. For 80 kilograms and 2 metres, BMI is 80 divided by 4, or 20.0. An imperial check can use a known pair and the factor 703. Repeating the arithmetic independently helps catch a unit-menu mistake.

The formula is sensitive to height because height is squared. A small height error affects the denominator twice, while weight enters linearly. This is another reason to measure rather than estimate when the number will be recorded.

Category thresholds should travel with reports because labels can be implemented differently in specialized populations or systems. State that this page uses below 18.5, 18.5 to below 25, 25 to below 30, and 30 or above.

If an organization uses another validated protocol, follow it. Do not alter the displayed category text and imply that PWRKIT calculated a different standard.

BMI cannot identify why weight changed. Fluid shifts, illness, medication, training, growth, and measurement conditions require context beyond the formula. A surprising result should lead to input verification and appropriate professional discussion, not self-diagnosis.

When comparing two readings, use the same formula and units. Converting one measurement with rounded values can create an artificial difference. Keep original measurements and conversion details so the trend can be checked.

The Copy action transfers the displayed one-decimal BMI, category, and screening disclaimer. It does not include height, weight, or selected units. Add those inputs separately when another person must reproduce the result.