Find your ideal weight for a target BMI

What the Ideal Weight by BMI Calculator Does

This calculator tells you the body weight that corresponds to a target BMI (Body Mass Index) at your height. Instead of starting with your current weight and computing your BMI, it works backward: you choose a BMI value you want to reach, enter your height, and it returns the matching weight in kilograms.

It is useful for anyone setting a weight goal, including people who want to land inside the normal BMI range (18.5 to 24.9), clinicians and trainers checking healthy weight bands, and anyone curious about the weight at a specific BMI. Because BMI does not account for muscle mass, frame size, age, or sex, treat the result as a general reference rather than a precise personal target.

How It Works: The Formula

BMI is defined as weight in kilograms divided by height in meters squared. Rearranging that equation to solve for weight gives the formula this tool uses:

weight (kg) = targetBMI x (heightCm / 100)^2

The height is divided by 100 to convert centimeters to meters, then squared. Multiplying by your chosen BMI returns the weight that produces exactly that BMI. To get a healthy weight range rather than a single number, run the formula twice: once with a BMI of 18.5 (lower bound) and once with 24.9 (upper bound).

Worked Example

Suppose someone is 175 cm tall and wants the weight for a target BMI of 22 (a value near the middle of the normal range).

First convert height: 175 / 100 = 1.75 m. Square it: 1.75^2 = 3.0625. Multiply by the target BMI: 22 x 3.0625 = 67.4 kg.

So a 175 cm person reaches a BMI of 22 at about 67 kg. Using the same height, BMI 18.5 gives 18.5 x 3.0625 = 56.7 kg and BMI 24.9 gives 24.9 x 3.0625 = 76.3 kg. The full normal-weight range at 175 cm is therefore roughly 57 to 76 kg.

BMI Categories to Aim For

The World Health Organization classifies adult BMI into standard bands. Picking a target BMI inside the normal range is a common starting point:

• Underweight: below 18.5
• Normal weight: 18.5 to 24.9
• Overweight: 25.0 to 29.9
• Obese: 30.0 and above

Tips and Common Mistakes

Measure height accurately. Because height is squared in the formula, a small error has an outsized effect: at BMI 22, being off by 2 cm shifts the target weight by more than 1.5 kg.

Keep your units consistent. Enter height in centimeters and read weight in kilograms. If you think in feet, inches, or pounds, convert first (1 inch = 2.54 cm, 1 kg = 2.2 lb).

• Do not treat one BMI value as a hard rule. A range (for example 20 to 24) is more realistic than a single number.
• BMI can mislead for very muscular people, athletes, the elderly, pregnant women, and children, who need age- and sex-specific charts.
• A target weight is not the same as a safe rate of change. Aim for gradual progress, typically 0.25 to 0.5 kg per week.
• BMI ignores body fat distribution; pairing it with a waist measurement gives a fuller picture of health.