OmniTools

BMI Calculator

Calculate body mass index with Metric / Imperial units and WHO health range.

Basis: The WHO international BMI classification (kg/m²) — the US CDC uses the same cut-offs of 18.5 / 25 / 30·2026-08-28 verified·Not reviewed by a medical professional·Editorial policy

Before you rely on this

BMI uses only height and weight, so it cannot separate muscle from fat. Muscular athletes read as overweight and older adults who have lost muscle read as normal. The WHO international cut-offs and the Asia-Pacific cut-offs differ — check which one you are reading.

Tool Overview & Key Purpose

Calculate Body Mass Index (BMI) to determine health weight status using WHO and Asia-Pacific standards.

Step-by-Step Usage Instructions

1STEP 1

Choose preferred measurement unit system (Metric: cm/kg or Imperial: ft/in/lbs).

2STEP 2

Provide age, gender, height, and weight.

3STEP 3

Check calculated BMI index and target healthy weight range.

4STEP 4

Locate your position on the visual weight status chart.

Real-World Scenarios & Practical Cases

3 Practical CasesScenario #1

Adult Height 5ft 10in, Weight 165 lbs

BMI score is 23.7, sitting comfortably in the Healthy Normal Weight range (18.5 - 24.9).

Normal weight reduces long-term cardiovascular risks.Scenario #2

Fitness & Weight Loss Goal Setting

From 195 lbs (BMI 28.0 Overweight) aiming for target BMI 23.0 requires reaching 160 lbs.

Set sustainable progressive weight loss targets of 1-2 lbs per week.Scenario #3

Identifying Underweight Health Risks

A BMI under 18.5 alerts users to potential nutrient deficiencies or muscle loss requiring dietary adjustment.

Underweight status warrants muscle-building nutrition.BMI formulaBMI = weight(kg) / [height(m)]² OR [weight(lbs) / (height(in))²] × 703

Pro Tips & Key Considerations

BMI does not distinguish muscle mass from fat mass; athletic individuals may score high despite low fat.Asia-Pacific criteria define overweight at BMI >= 23 and obesity at BMI >= 25.

Frequently Asked Questions (FAQ)

Sources & References

World Health Organization — Obesity and Overweight CDC — About Body Mass Index (BMI)

Basis: The WHO international BMI classification (kg/m²) — the US CDC uses the same cut-offs of 18.5 / 25 / 30 · 2026-08-28 verified