BMI Calculator

Height

100–250 cm

Weight

30–300 kg

22.9
Your BMI is
Normal Weight
bmi_calculator.scale
1518.5253040+
BMI is a screening tool and not a diagnostic tool. Consult a healthcare professional for medical advice.

Body Mass Index without the fluff

BMI compares your weight to your height and helps flag when weight is creeping too low or too high.

Use the calculator above to get your number, then use the context below to decide what to do next.

Quick formula

BMI = weight (kg) ÷ [height (m)]². Switch to imperial units above if you prefer pounds and inches—we will convert the math for you.

Tip: divide your height in centimetres by 100 to get metres before squaring the value.

What this tool does well

  • Gives a repeatable measurement in seconds.
  • Highlights when lifestyle or medical follow-up may be useful.
  • Works for most adults when other lab data is unavailable.

BMI categories at a glance

Underweight

Under 18.5

Review your eating pattern, recent illness, or talk with a clinician if the number surprises you.

Healthy range

18.5 – 24.9

Stay active, eat well, and keep an eye on gradual changes over the year.

Overweight

25.0 – 29.9

Combine BMI with waist measurements or labs to decide on next steps.

Obesity

30.0 and higher

Pair this number with a doctor visit or structured program so you get support instead of guesswork.

How to get a reliable reading

  1. Pick metric or imperial units before entering numbers.
  2. Use a recent, morning weight for the most stable value.
  3. Measure height without shoes and stand tall against a wall.
  4. Re-check monthly or when your routine changes.

Make sense of the result

  • Compare today’s BMI to last season, not just last week.
  • Note symptoms such as fatigue, joint pain, or appetite changes.
  • Share the number with your healthcare provider if you have diabetes, heart disease, or are pregnant.

When BMI is not enough

  • Strength athletes can score high because of muscle, not fat.
  • Kids and teens should use age-specific growth charts.
  • Older adults with low muscle may have a “normal” BMI despite risk.

Quick answers

How often should I check BMI?

Once a month is plenty for most people. Log the value with the date so you can spot trends.

What if the number looks off?

Double-check that you used the right units, then compare against a tape-measure reading or body-fat scan if available.

Can BMI support a training goal?

Yes—use BMI for a high-level target, then lean on strength tests, performance logs, or body-fat measurements for finer control.