Ideal Weight Calculator

What is an ideal weight calculator?

An ideal weight calculator estimates a target body weight for your height, giving you both a single reference figure and a realistic healthy range. This tool combines two well-known methods: the Devine formula, which returns one ideal body weight (IBW) in kilograms, and the healthy BMI range (BMI 18.5 to 24.9), which returns a band of weights that are considered healthy for your height.

It is a quick screening estimate for adults, not a personalised prescription. Two people of the same height can be perfectly healthy at different weights, so the most useful output is usually the range rather than the exact number.

How does the ideal weight calculator work?

The tool runs two calculations from your height and sex.

1. Devine formula (ideal body weight). Devine starts from a base weight and adds a fixed amount for every inch you stand above 5 feet:

Men:   IBW (kg) = 50   + 2.3 × (height in inches − 60)
Women: IBW (kg) = 45.5 + 2.3 × (height in inches − 60)

Here 60 inches is exactly 5 feet, the height where the base weight applies. Each inch above that adds 2.3 kg. If you enter height in centimetres, the tool converts it to inches first (1 inch = 2.54 cm) before applying the formula.

2. Healthy BMI range. Body Mass Index is weight ÷ height² in metric units, so rearranging it gives a weight band for any height:

Lower weight (kg) = 18.5 × height(m)²
Upper weight (kg) = 24.9 × height(m)²

So the result has two parts: Devine gives one ideal figure, while the BMI calculation gives a healthy weight range around it. For most heights the Devine number falls inside that range, which is a useful sanity check.

Examples

Here are worked calculations that match the tool exactly. All Devine figures are in kilograms and use height in inches over 60.

Example 1 — Man, 175 cm (68.9 in)

• Inches over 5 ft: 68.9 − 60 = 8.9
• Devine: 50 + 2.3 × 8.9 = 70.5 kg
• Healthy BMI range at 1.75 m: 18.5 × 1.75² = 56.7 kg to 24.9 × 1.75² = 56.7 to 76.3 kg
• The 70.5 kg ideal weight sits inside the healthy band.

Example 2 — Woman, 165 cm (64.96 in)

• Inches over 5 ft: 64.96 − 60 = 4.96
• Devine: 45.5 + 2.3 × 4.96 = 56.9 kg
• Healthy BMI range at 1.65 m: 18.5 × 1.65² = 50.4 kg to 24.9 × 1.65² = 50.4 to 67.8 kg

Example 3 — Man, 5 ft 10 in (70 in)

• Inches over 5 ft: 70 − 60 = 10
• Devine: 50 + 2.3 × 10 = 73.0 kg
• Height 70 in is 1.778 m, so the healthy BMI range is 18.5 × 1.778² to 24.9 × 1.778² = 58.5 to 78.7 kg

Example 4 — Woman, 5 ft 6 in (66 in)

• Inches over 5 ft: 66 − 60 = 6
• Devine: 45.5 + 2.3 × 6 = 59.3 kg
• Height 66 in is 1.6764 m, so the healthy BMI range is 52.0 to 70.0 kg

A useful edge case: someone exactly 5 feet (60 in) tall gets the base weight with no addition, so the Devine ideal weight is 50.0 kg for a man and 45.5 kg for a woman.

Ideal body weight by height (Devine)

This reference table shows the Devine ideal body weight for common heights, for both men and women. Add or subtract from your nearest row, or enter your exact height in the tool above for a precise figure.

Height	Men (Devine)	Women (Devine)
5’0” (60 in / 152 cm)	50.0 kg	45.5 kg
5’2” (62 in / 157 cm)	54.6 kg	50.1 kg
5’4” (64 in / 163 cm)	59.2 kg	54.7 kg
5’6” (66 in / 168 cm)	63.8 kg	59.3 kg
5’8” (68 in / 173 cm)	68.4 kg	63.9 kg
5’10” (70 in / 178 cm)	73.0 kg	68.5 kg
6’0” (72 in / 183 cm)	77.6 kg	73.1 kg
6’2” (74 in / 188 cm)	82.2 kg	77.7 kg

What is the ideal weight calculator used for?

This calculator is handy whenever you want a quick, height-based weight reference, such as:

• Setting a healthy weight goal that is grounded in your height rather than a round number.
• Sanity-checking a target by comparing the single Devine figure against the wider BMI range.
• Clinical-style estimates, since the Devine formula was originally designed to help calculate medication doses based on lean body size.
• Fitness planning, as a starting point before refining goals with body composition in mind.

For a fuller picture you can pair it with the BMI calculator to see your current category, or the water intake calculator to plan daily hydration around your body weight.

Tips and common mistakes

A few practical points help you read the result correctly:

• Treat the number as a midpoint, not a must-hit target. The healthy BMI range exists precisely because many weights are healthy for one height.
• Match the units when you compare. Devine works from inches over 60; the BMI range works from metres. The tool handles both, but mixing them by hand causes errors.
• Do not over-trust the single figure for very tall or very short people. The fixed 2.3 kg per inch makes Devine drift high for tall frames and low for short ones.
• Remember frame and muscle. A muscular person can sit above their Devine weight and still be lean, because the formula ignores body composition.
• Round sensibly. A result of 70.5 kg is an estimate, not a precise prescription, so do not chase the last decimal.

Limitations and notes

The Devine formula is simple and widely used, but that simplicity is also its main weakness. It uses only height and sex and ignores age, frame size, muscle mass and body-fat distribution. Because it adds a flat 2.3 kg per inch from a fixed base, it can over- or under-estimate at the extremes of height, and it was built for dosing calculations rather than as a personal weight goal.

The healthy BMI range is broader and more realistic for everyday use, but BMI itself has known limits: it cannot tell muscle from fat, and some populations face different risk thresholds. Read both outputs together, and lean on the range rather than the single number.

Health disclaimer: This ideal weight calculator provides a general estimate for information and education only. It is not medical advice or a diagnosis. Healthy weight depends on many factors this tool cannot see, so consult a qualified healthcare professional before making decisions about your weight or health.

For more fitness and body tools, try the body fat calculator to refine your goal by composition, the BMR calculator to estimate daily calories, or browse the full health & medical category.