BMI, Ideal Weight & Calorie Calculator

BMI & Calorie Calculator
Your BMI, the weight range behind it, and what your body burns in a day.
Your BMI
22.5
Healthy weight
18.5
23
25
30
35
Standard weight (BMI 22)
63.6 kg
Healthy weight range
53.5 kg – 66.5 kg
To reach that range
Already inside it
Basal metabolic rate
1,568 kcal
Daily calories to maintain
2,155 kcal
To lose about 0.45 kg a week
1,655 kcal
To gain weight
2,455 kcal
BMI describes a population, not a person: it cannot tell muscle from fat. Everything here is general information, not medical advice.

A BMI number means little until you know which scale it is being read against. A BMI of 24 sits inside the healthy band on the WHO scale and inside pre-obesity on the Asia-Pacific one that Korea and Japan use. This page offers both and says on screen which one produced the verdict. It also refuses to stop at the single number: you get the weight range that band corresponds to, your basal metabolic rate and daily calorie need, and — if you measure it — what your waist says that BMI cannot.

How to use BMI, Ideal Weight & Calorie Calculator

  1. Choose your units. Switching between cm/kg and ft/lb converts what you already typed, so nothing needs measuring twice.
  2. Enter sex and age. Neither affects BMI itself; they are used for the metabolic rate and for the abdominal-obesity threshold.
  3. Enter height and weight. Those two alone produce the BMI and the healthy weight range.
  4. Waist is optional but worth the minute. Measure standing, at the navel, after breathing out — bare skin, not the waist size of your trousers.
  5. Pick an activity level. This drives the daily calorie figures, and most people choose one level higher than their week actually looks.
  6. Choose the BMI scale. The coloured bands under the number redraw to match whichever standard you selected.

Tips & gotchas

  • In Korea and Japan obesity starts at BMI 25, not the WHO’s 30. East Asian populations carry more visceral fat at the same BMI, and reach the diabetes and hypertension risk of a much higher Western band earlier.
  • Standard weight is calculated at BMI 22 — the middle of the healthy band, and the point where population studies have long shown the lowest disease incidence.
  • Waist divided by height is often a better signal than BMI, and it comes with a sentence you can remember: keep your waist under half your height. It needs almost no adjustment for age or ethnicity.
  • Carrying real muscle pushes BMI into the overweight bands. BMI is weight over height squared and knows nothing about what the weight is made of, so if you train, trust the waist-to-height figure more.
  • A warning appears if the weight-loss target drops below the usual floor. A 500 kcal daily deficit is roughly 0.45 kg a week, which is too steep a cut for someone whose maintenance figure is already low.
  • Your height and weight are stored in this browser and are never transmitted. On a page about your body, that ought to be more than a slogan.

Frequently asked questions

Why does Korea call BMI 25 obese?

Because of risk, not build. In 2004 the WHO Western Pacific Region and the International Obesity Task Force published separate Asia-Pacific thresholds, which the Korean Society for the Study of Obesity adopted. East Asian populations carry a higher proportion of visceral fat at any given BMI, and around BMI 25 already show the type 2 diabetes and hypertension risk that Western populations reach nearer BMI 30. So obesity begins at 25 and the 23–25 band ahead of it is called pre-obesity. Switch the scale on this page to WHO and you can watch the same weight change its name.

My BMI is normal but my waist is not

That is one of the things BMI is known to miss — sometimes called normal-weight obesity: little limb muscle, plenty of visceral fat. Waist measurements are what catch it. A waist of 90 cm in men or 85 cm in women counts as abdominal obesity regardless of BMI, and a waist over half your height says the same thing. Enter a waist measurement and both verdicts appear in the results.

Which formula is used for metabolic rate?

Mifflin-St Jeor: 10 × weight in kg + 6.25 × height in cm − 5 × age, then +5 for men and −161 for women. It tracks measured values in modern populations better than the older Harris-Benedict equation and is the one dietetic practice now prefers. Multiplying it by the activity factor gives the maintenance figure. Every such equation carries roughly ±10% of individual variation, so treat the number as a starting point and adjust it against two weeks of real weight change.

Does this work for children?

No. Under 19, healthy BMI changes with age and sex as a child grows, so it is read against percentile charts rather than fixed bands — typically the 85th percentile for overweight and the 95th for obesity. Enter an age under 19 and the page says so rather than pretending otherwise.

How fast should I lose weight?

0.5 to 1 kg a week, or 2 to 4 kg a month, is the range usually recommended. A kilogram of body fat is around 7,700 kcal, which is why a 500 kcal daily deficit works out at roughly 0.45 kg a week. Go faster and more of the loss comes from muscle, and metabolic rate falls with it, which is what makes fast loss so hard to hold. That is why the only deficit this page offers is 500 kcal — and why it warns you when even that lands too low.

Does a normal BMI mean I am healthy?

It should not be read that way. BMI uses two numbers and knows nothing about muscle versus fat, where that fat sits, or your blood pressure and blood sugar. It was built to describe the distribution of a population, not to diagnose a person. Read it next to waist measurements, blood work and what your body can actually do — and when a real judgement is needed, that conversation belongs with a clinician, not a web page.

Related tools
Character Counter
PDF Tools — Merge, Split, Rotate
Screen Recorder
Online Timer & Stopwatch