Fitness & Health

BMI Calculator for Adults with Category Results

Calculate body mass index from height and weight, then view BMI category ranges and quick interpretation for adult screening.

Search intent guide

Use this page when you need a fast answer to bmi calculator

Use this BMI calculator when you want a fast body-size screening metric based on height and weight. It is most useful as a first-pass classification, not as a full body-composition or health diagnosis.

bmi calculatorBMI Calculator2 examples

Editorial review

Reviewed by Smart Calculator Tools Editorial TeamUpdated April 4, 2026

Best for

  • Quick adult height and weight screening
  • Tracking BMI category changes over time
  • Adding context before moving to waist or body-fat metrics

Before you start

  • Use consistent height and weight measurements each time
  • Do not treat BMI alone as a body-fat measurement
  • Pair the result with waist or composition context when needed

Inputs

BMI uses height and weight to estimate body mass for adults.

Results

BMI categories are general guidelines for adults.

Body mass index

22.86

Category

Normal

Healthy weight range

56.66 - 76.26 kg

Target weight (BMI 22)

67.38 kg

BMI Prime

0.91

Ponderal Index

13.06

BMI scale

102540

Target weights by BMI

BMIWeight
18.556.66 kg
2576.56 kg
3091.88 kg
35107.19 kg

BMI classifications

CategoryBMI range
Underweight< 18.5
Normal18.5 - 24.9
Overweight25 - 29.9
Obesity30+

BMI is a screening metric, not a diagnosis. Consider body composition and overall health.

References

  • World Health Organization BMI classification
  • CDC BMI guidance for adults and children
  • US Navy and academic references for Ponderal Index

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How this BMI Calculator works

Calculates body mass index from height and weight and classifies the result for adults. It also provides BMI Prime, Ponderal Index, and a healthy weight range based on height so you can interpret the result with more context.

Best use cases

  • Get a fast adult screening metric from height and weight before looking at deeper body-composition tools.
  • Track broad weight-status trends over time with one simple, standardized measurement.
  • Check whether current weight falls inside a common healthy-weight range for a given height.

Inputs

  • Height and weight in Metric, US, or Other units
  • Age and sex for context
  • Unit selection and conversions

Outputs

  • BMI value and category
  • Healthy weight range for the given height
  • BMI Prime and Ponderal Index
  • BMI scale position

Assumptions

  • Adult BMI categories are screening guidelines
  • Children and teens require age- and sex-specific charts
  • BMI does not directly measure body fat

Common mistakes

  • Treating BMI like a diagnosis even though it is only a screening tool and not a direct fat measurement.
  • Applying adult BMI categories to children or teens, who require age- and sex-specific growth charts.
  • Overreacting to a single result instead of looking at trend, waist size, and other health context.

Tips

  • Use consistent units for better accuracy
  • Consider waist and body composition for more context
  • Track trends over time rather than a single value

BMI Calculator formula guide

Use these bmi calculator formulas to audit the output or explain it to someone else.

4 formulas

BMI = weight(kg) / height(m)^2
BMI Prime = BMI / 25
Ponderal Index = weight(kg) / height(m)^3
Healthy Range = 18.5-24.9 * height(m)^2

BMI Calculator examples

Review a ready-made bmi calculator scenario, copy it, then tweak inputs to match your case.

Example

2 inputs2 outputs

Metric example

Inputs

  • Weight 70 kg and height 175 cm
  • Age 30 with adult category

Outputs

  • BMI about 22.9 and Normal category
  • Healthy range about 56 to 76 kg

Uses standard adult categories for interpretation.

Example

2 inputs2 outputs

US example

Inputs

  • Weight 154 lb and height 5 ft 9 in
  • Age 30 with adult category

Outputs

  • BMI about 22.7 and Normal category
  • BMI Prime about 0.91

Same outcome with different units and conversions.

Adult BMI categories

4 of 4 rows
CategoryRange
Underweight< 18.5
Normal18.5 - 24.9
Overweight25 - 29.9
Obesity30+

Categories apply to adults and are not diagnostic.

BMI points on scale

Highest: Obese (32)Lowest: Under (17)
CategoryBMI value

Focus point

Under

17

Position

#1 of 4

Original order

Share of total

17.35%

Total: 98

PositiveNegative

Sample values placed within each category band.

BMI is a screening tool and not a diagnosis.

References

  • World Health Organization BMI classification
  • CDC BMI guidance for adults and children
  • Ponderal Index background

Learn more

Guides connected to the bmi calculator

Use these short guides when you want the decision framework behind the numbers, not just the raw output.

Category guide

Fitness & Health Calculator Guide

Use body, nutrition, and training calculators as planning tools rather than diagnoses, and focus on trends instead of one-off numbers.

FAQ

BMI Calculator FAQ

What does the BMI Calculator do?

Calculates body mass index from height and weight and classifies the result for adults. It also provides BMI Prime, Ponderal Index, and a healthy weight range based on height so you can interpret the result with more context. It is part of our fitness & health toolkit.

When should I use this calculator?

Use it when you need to Get a fast adult screening metric from height and weight before looking at deeper body-composition tools. Track broad weight-status trends over time with one simple, standardized measurement.

What inputs do I need?

Typical inputs include Height and weight in Metric, US, or Other units, Age and sex for context, Unit selection and conversions.

How are the results calculated?

We follow the formulas and assumptions outlined in the "How this calculator works" section. You will see outputs like BMI value and category, Healthy weight range for the given height, BMI Prime and Ponderal Index.

What mistakes should I avoid?

Common mistakes include Treating BMI like a diagnosis even though it is only a screening tool and not a direct fat measurement. Applying adult BMI categories to children or teens, who require age- and sex-specific growth charts.

Can I share or download the results?

Use the Copy link or Print buttons to share your results. If a table or chart appears, you can download the data as CSV.

Is my data stored?

No. Calculations run in your browser and we do not store your inputs.

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