How to Calculate Ideal Weight: A Step-by-Step Guide

Updated 5 Oct 2026 in Health & Fitness

Gives an ideal-weight estimate and the healthy weight range for your height.

Health numbers are most useful when you track them consistently. A quick calculation turns everyday measurements into something you can act on, whether that is planning meals, training for a run or preparing for a clinic visit.

What you need

• Sex
• Height (cm)

Step by step

1. Enter the sex.
2. Enter the height (cm).
3. The results update as you type, or press Calculate.
4. Read the ideal weight (devine) first, then the supporting figures below it.

The formula

Devine: 50 kg (men) or 45.5 kg (women) + 2.3 kg per inch above 5 feet.

Worked example

For example, with these inputs:

• Sex: Male
• Height (cm): 170

the calculator returns:

• Ideal weight (Devine): 65.94 kg
• Healthy range for Asians (BMI 18.5–22.9): 53.46 kg (lower)
• Upper healthy weight: 66.18 kg

A second example

Now change the inputs to:

• Sex: Male
• Height (cm): 212

the calculator returns:

• Ideal weight (Devine): 103.97 kg
• Healthy range for Asians (BMI 18.5–22.9): 83.15 kg (lower)
• Upper healthy weight: 102.92 kg

Practical tips

• Track trends over weeks rather than reacting to a single reading.
• Measure at the same time of day, ideally in the morning, for consistent readings.
• Formulas give estimates for the average person; your doctor can account for your history and body composition.
• See a healthcare professional before big changes to diet or exercise, especially if you have a medical condition.

Background

Singapore's tropical climate means you lose more fluid through sweat, even when you are not exercising. Thirst, urine colour and how you feel are good guides, and needs rise during outdoor activity or heat waves.

Any health calculator gives a general estimate. If a result worries you, or you are pregnant, managing a chronic condition or planning a big change in diet or exercise, speak to a doctor, polyclinic or dietitian.

Research has shown that Asians tend to develop conditions such as type 2 diabetes and heart disease at lower body weights than Europeans. That is why the Health Promotion Board recommends lower BMI cut-offs for Singaporeans, with 23 marking the start of moderate risk.

Related calculations

• Daily Water Intake Calculator: A rough guide to daily fluid needs in Singapore's hot, humid climate.
• Calorie Deficit Calculator: Sets a daily calorie target for steady weight loss.
• Pregnancy Due Date Calculator: Estimates your due date using Naegele's rule.
• Ovulation Calculator: Estimates ovulation and the fertile window.

Want to skip the arithmetic? The free Ideal Weight Calculator does all of this instantly and updates as you type.

Run your own numbers: Ideal Weight Calculator