Clear BMI Calculator
Enter your height and weight to get your Body Mass Index and see which category you fall into. Switch between imperial and metric anytime.
| Category | — |
| Healthy weight range for your height | — |
How it works
Imperial: BMI = 703 × weight (lbs) ÷ height (in)2. Metric: BMI = weight (kg) ÷ height (m)2. Categories follow CDC cutoffs: under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight, 30+ obese.
Formula & worked example
Formula: BMI = 703 × weight (lb) ÷ height (in)², or weight (kg) ÷ height (m)². Categories: under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight, 30+ obese.
Worked example: At 180 lb and 5′10″ (70 in): 703 × 180 ÷ 4,900 = 25.8 — just inside the overweight band.
When to use this
- A quick screening number for a health form, sport or insurance questionnaire.
- You are tracking weight change and want the category context, not just the scale.
- You are setting a goal weight and want to know which BMI it corresponds to.
- A clinician mentioned BMI and you want to see where the bands sit for your height.
How to use it, step by step
- Choose imperial or metric.
- Enter height and weight as they are today.
- Read the BMI and its band.
- Use the healthy-range line to see the weights that correspond to BMI 18.5–24.9 at your height.
- If you train seriously, pair this with a body-fat estimate — BMI cannot see muscle.
What the inputs mean
| Input | What it is | Typical values |
|---|---|---|
| Height | Barefoot height | Adult range roughly 4′8″–6′8″ |
| Weight | Current body weight | Morning, post-bathroom is the consistent measure |
| Units | Imperial (lb/in) or metric (kg/cm) | BMI = 703 × lb ÷ in², or kg ÷ m² |
Another worked example
At 5′6″ and 160 lb, BMI is 25.8 — just inside the 'overweight' band (25–29.9). The same person at 148 lb would read 23.9, inside the healthy band, which shows how few pounds separate the categories at this height — and why the trend matters more than any single reading.
Frequently asked questions
What is a healthy BMI?
The CDC defines a healthy BMI as 18.5 to 24.9 for adults. Athletes with high muscle mass may score above 25 while still being healthy.
How accurate is BMI?
It's a quick population-level screen, not a body-fat measurement. Two people with the same BMI can have very different health profiles.
Should I convert my units first?
No — just pick Imperial or Metric above and enter your numbers as-is. The tool converts behind the scenes.
Why does BMI call muscular people overweight?
BMI is weight divided by height squared — it has no way to know what the weight is made of. A lean athlete at 5′10″ and 200 lb scores about 28.7. That is a known limitation, which is why waist size and body-fat percentage are the follow-up checks.
Is BMI used for children?
Not this adult scale. Children and teens are assessed on percentile curves by age and sex — a pediatric standard this calculator deliberately does not apply.
📊 Want the full picture?
Pair your BMI with your savings and health goals — our compound interest and savings goal calculators do the money math.