Ideal Weight Calculator

What Is an Ideal Weight Calculator?

This ideal weight calculator gives you your ideal body weight using five clinically-referenced formulas simultaneously. Rather than relying on a single number, this ideal weight calculator shows you a range of results — giving you a more realistic and nuanced target. The five formulas shown are Robinson, Miller, Devine, Hamwi, and the WHO healthy BMI range.

No single ideal weight calculator formula is perfect for everyone. However, together they give you a reliable range to work toward. In fact, most health professionals agree that being within a healthy BMI range with good fitness is more meaningful than hitting a specific ideal weight calculator number.

How Does the Ideal Weight Calculator Work?

This ideal weight calculator applies five different formulas to your height and sex. Each formula was developed for different clinical purposes. Here is a summary of each one.

Robinson Formula (1983)

Miller Formula (1983)

Devine Formula (1974)

Hamwi Formula (1964)

Healthy BMI Range

This ideal weight calculator also shows the weight range corresponding to a healthy BMI of 18.5–24.9. This is the World Health Organization’s standard healthy weight range. It is the most widely used reference for ideal weight and gives you a lower and upper boundary rather than a single target.

How to Use This Ideal Weight Calculator

1. Select your unit system — metric (cm and kg) or imperial (feet, inches, and lbs).
2. Select your sex — the ideal weight calculator applies sex-specific formulas for each method.
3. Enter your height — use your actual measured height for the most accurate ideal weight calculator result.
4. Click Calculate — all five formula results and the healthy BMI range appear instantly.

What Does Your Ideal Weight Calculator Result Mean?

This ideal weight calculator shows five different numbers. Each comes from a different clinical formula. Together they form a range. Here is how to interpret them.

• Average across formulas: The mean of the four IBW formula results. This is a useful single reference point if you want one number to aim for.
• Healthy BMI range: The weight range corresponding to BMI 18.5–24.9. This is the most clinically meaningful range shown by the ideal weight calculator.
• Individual formula results: Miller tends to be lowest; Hamwi tends to be highest. The variation between them reflects the genuine uncertainty in what “ideal weight” means at an individual level.

Is This Ideal Weight Calculator Accurate?

The ideal weight calculator formulas were developed for clinical use in hospital settings — primarily for calculating medication dosages based on lean body mass. They were not originally designed as weight loss targets. Therefore, treat them as reference points rather than precise goals.

According to the National Heart, Lung, and Blood Institute (NHLBI), the healthy BMI range of 18.5–24.9 is the most reliable general indicator of healthy weight for adults. Use this ideal weight calculator alongside our BMI Calculator and Body Fat Calculator for the most complete picture.

Ideal Weight Calculator for Women

Yes — this ideal weight calculator uses sex-specific formulas for women. Women naturally have a different body composition to men at the same height. The ideal weight calculator applies lower baseline values and different per-inch increments for women to reflect this biological difference.

Furthermore, women’s healthy weight can vary more than men’s due to differences in frame size, hormonal factors, and muscle mass. Therefore, the healthy BMI range shown by this ideal weight calculator is particularly useful for women — it gives a range rather than a single number.

Ideal Weight Calculator for Men

Yes — this ideal weight calculator uses sex-specific formulas for men. Men generally have higher baseline ideal weights than women at the same height due to greater average muscle mass and bone density. The Hamwi and Devine formulas in particular were originally developed in male clinical populations.

For muscular men, the ideal weight calculator result may seem lower than their actual healthy weight. In that case, the upper end of the healthy BMI range — or even a body fat calculator result — is a more meaningful reference than the IBW formula average.

Common Mistakes When Using an Ideal Weight Calculator

• Treating the ideal weight calculator number as a strict target: These are reference points, not mandates. Being within the healthy BMI range with good fitness and energy levels is more meaningful than matching the ideal weight calculator exactly.
• Ignoring frame size: People with larger bone frames naturally weigh more than those with smaller frames at the same height. The ideal weight calculator cannot account for frame size — adjust your target toward the upper or lower end of the range accordingly.
• Focusing on weight rather than composition: Weight alone does not tell the full story. A person within the ideal weight calculator range can still have high body fat and low muscle mass. Use our Body Fat Calculator alongside this tool.

Ideal Weight Calculator — Frequently Asked Questions