🏋️ Ideal Weight Calculator

Calculate your ideal body weight based on height and gender.

Calculate Now

What is Ideal Weight Calculator?

This tool gives you a quick reference point for a "healthy" body weight based purely on your height, using a simplified version of the classic Broca index — one of the oldest rule-of-thumb methods doctors have used to eyeball healthy weight ranges long before BMI charts became common. It's not a diagnosis or a target you must hit exactly, but a useful anchor when you're setting a realistic weight goal.

Ideal Weight Formula

Base height factor: h = height in cm − 100
Men: Ideal Weight = h − (h × 0.10)
Women: Ideal Weight = h − (h × 0.15)

Healthy Range = Ideal Weight × 0.9 to Ideal Weight × 1.1

Worked Example

For a man who is 175 cm tall:

h = 175 − 100 = 75
Ideal Weight = 75 − (75 × 0.10) = 75 − 7.5 = 67.5 kg
Healthy Range = 60.75 kg to 74.25 kg

So a 175 cm man landing anywhere roughly between 61 kg and 74 kg would fall within this formula's suggested healthy band, with 67.5 kg as the single reference figure.

How to Use This Calculator

  1. Enter your height in centimetres.
  2. Click Calculate.
  3. Read your ideal weight figure along with the healthy weight range shown below it.

Things to Keep in Mind

Height-only formulas like this one ignore muscle mass, bone density, and body frame size, so a muscular athlete may sit well above this number while still being lean and healthy. It works best as a rough screening tool rather than a strict target — pairing it with a BMI check or a body fat estimate gives a fuller picture. If you're planning a significant weight change for medical reasons, loop in a doctor or dietitian rather than chasing this number alone.

💡 Tip: Use this figure alongside the BMI Calculator — if the two disagree noticeably, body composition (muscle vs. fat) is often the reason why.

Limitations to Keep in Mind

The Broca-based formula behind this calculator was developed in the 19th century as a simple clinical shorthand, long before modern body composition science existed — it doesn't account for frame size, muscle mass, or ethnicity-specific body composition differences, including those documented in South Asian populations. It tends to under-represent a healthy weight for naturally broad-framed or muscular individuals and over-represent it for those with a small frame. It also isn't meant for children, teenagers still growing, pregnant women (whose healthy weight gain is tracked separately by trimester), or older adults, where slightly higher body weight is sometimes associated with better outcomes than in younger adults. Because it uses height alone, two people of the same height with very different builds will get the identical "ideal" figure, even though a healthy weight for each of them may genuinely differ. Use this as one data point among several — including BMI, waist circumference, and a doctor's clinical judgment — rather than a strict number to chase.

Frequently Asked Questions

Q: Why does this "ideal weight" figure differ from the middle of my BMI's normal range?
A: The two use completely different formulas. This calculator is based on the Broca index, a height-only formula from the 1800s, while BMI relates weight to the square of height. It's common for the two methods to suggest slightly different numbers — neither is more "correct" than the other, they're just different reference points.

Q: Isn't the Broca formula outdated compared to modern methods?
A: In a sense, yes — it predates modern body composition research and doesn't factor in muscle, bone density, or fat distribution. It remains in use mainly because it's simple and gives a quick reference figure, but it works best alongside newer measures like BMI or body fat percentage rather than on its own.

Q: Does my body frame size (small, medium, large) change what's "ideal" for me?
A: Yes, in reality, though this basic formula doesn't adjust for it. Someone with a naturally larger bone structure and broader shoulders can carry more healthy weight than someone of the same height with a smaller frame — wrist circumference is sometimes used as a rough frame-size indicator, but this calculator doesn't include that adjustment.

Q: I'm several kilograms outside the suggested healthy range — should I be concerned?
A: Not automatically. Being outside this range doesn't necessarily indicate a health problem, especially if you're muscular, have a large frame, or your weight has been stable for years with good bloodwork. It's a prompt to look at the fuller picture — BMI, body fat, waist size, and how you feel — rather than a definitive verdict.

Q: Can I use this number to set a strict personal weight-loss or weight-gain goal?
A: It's better used as a rough reference than a strict target. For a personalised, medically sound weight goal — especially if you have existing health conditions — consult a doctor or dietitian who can consider your full health profile rather than a single height-based formula.

Q: Are there other ideal weight formulas besides Broca's?
A: Yes — the Devine formula, the Robinson formula, and the Hamwi formula are all commonly cited alternatives, each using slightly different constants and typically returning numbers within a few kilograms of one another for the same height. None of these older formulas is definitively "more correct"; they're all rough clinical shorthand developed decades apart, which is one reason this calculator presents a healthy range rather than a single rigid figure.

More Worked Examples

Applying the same formula to a few different heights shows how the ideal weight and healthy range scale:

  • Woman, 155 cm tall: h = 155 − 100 = 55. Ideal Weight = 55 − (55 × 0.15) = 55 − 8.25 = 46.75 kg. Healthy Range = 42.1 kg to 51.4 kg.
  • Man, 182 cm tall: h = 182 − 100 = 82. Ideal Weight = 82 − (82 × 0.10) = 82 − 8.2 = 73.8 kg. Healthy Range = 66.4 kg to 81.2 kg.
  • Woman, 168 cm tall: h = 168 − 100 = 68. Ideal Weight = 68 − (68 × 0.15) = 68 − 10.2 = 57.8 kg. Healthy Range = 52.0 kg to 63.6 kg.

Ideal Weight vs BMI: Which Should You Follow?

These two calculators often give slightly different pictures of a "healthy" weight, and it helps to understand why rather than assuming one is wrong. BMI relates weight to the square of height and was designed for population-level statistics, while the Broca-based formula here is a much older, simpler height-only rule from 19th-century clinical practice. They tend to agree reasonably well in the middle of the height range but diverge more at the extremes, where very tall or very short individuals see a bigger gap. Rather than treating either as final, use them together — if they disagree by a wide margin, frame size, muscle mass, or ethnicity-specific body composition likely explains it, and a doctor can help interpret which matters more for you.

📅 Last reviewed: July 2026 · Formulas verified against RBI/SEBI/IT Dept guidelines.