Ideal Weight Calculator — Healthy Weight Range Free

Q: Which ideal weight formula is most accurate?

No single formula is 'most accurate' — they were all developed from population averages. The Devine formula is most widely used in medicine, but the BMI-based healthy range (18.5–24.9) is generally the most practical guide for everyday health.

Learn

Understanding Ideal Weight

Why "ideal weight" is a range — not a single magic number.

🧮 What Are These 4 Formulas?

Each formula was developed by researchers trying to estimate a healthy weight from height alone:

Devine (1974): The most widely used formula in medicine — originally created to calculate drug dosages. Men: 50 kg + 2.3 kg per inch over 5 feet. Women: 45.5 kg + 2.3 kg per inch over 5 feet.
Robinson (1983): A refinement of Devine based on larger population data, giving slightly lower estimates.
Miller (1983): Another Devine update that tends to give the lowest estimates of the four.
Hamwi (1964): The oldest — developed for clinical dietetics. Men: 48 kg + 2.7 kg per inch over 5 feet. Women: 45.5 kg + 2.2 kg per inch over 5 feet.

The fact that they disagree by 2–4 kg tells you something important: there is no single perfect weight — only a healthy range.

📊 Quick Reference: Healthy Weight by Height

Height	Healthy Range (BMI 18.5–24.9)
150 cm (4'11")	41.6 – 56.0 kg
160 cm (5'3")	47.4 – 63.7 kg
170 cm (5'7")	53.5 – 72.0 kg
175 cm (5'9")	56.7 – 76.3 kg
180 cm (5'11")	59.9 – 80.7 kg
190 cm (6'3")	66.8 – 89.9 kg

⚠️ What These Formulas Don't Account For

Muscle mass: A muscular athlete may healthily weigh 5–10 kg more than any formula suggests. Muscle is denser than fat.
Body frame: People with naturally larger bone structures can carry more weight healthily. A rough check: wrap your thumb and finger around your wrist — if they don't touch, you likely have a larger frame.
Age: Older adults (65+) may do best at the higher end of the healthy range — research links slightly higher weight with better outcomes in later life.
Ethnicity: Health risks begin at different weights for different populations. Asian adults, for example, may face increased risk at the lower end of the "healthy" range.

Bottom line: Treat your result as a starting target, not a verdict. How you feel, perform, and what your body fat percentage shows matter just as much.

🎯 Which Number Should You Actually Aim For?

Here's a practical approach:

If you're far from the range: Aim for the closest edge of your healthy BMI range first — not the middle. Reaching it is a huge health win on its own.
If you're inside the range: You're already in a healthy zone. Focus on body composition (body fat %) and fitness rather than the scale.
If you lift weights: Use body fat percentage as your main guide and treat these formulas as loose references.
Set process goals too: "Walk 8,000 steps daily" is more controllable than "lose 10 kg" — and it gets you there.

🚀 Reaching Your Ideal Weight Safely

To lose: A 400–500 kcal daily deficit produces ~0.5 kg of fat loss per week. At that pace, 10 kg takes about 5 months — and is far more likely to stay off than crash dieting.
To gain: A 250–300 kcal daily surplus with strength training builds roughly 0.25 kg per week, mostly muscle.
Either way: Prioritize protein (1.6–2.2 g per kg daily), lift weights 2–4 times weekly, and sleep 7–9 hours. These three habits do more for your body composition than any number on the scale.

FAQs

Ideal Weight Questions, Answered

Quick answers to common questions.

What is my ideal weight?

Your ideal weight depends on your height, gender, age, and body frame. For most adults, a BMI-based healthy range is the best guide: for someone 175 cm tall, that's roughly 57–76 kg. Use this calculator for your personal range.

Which ideal weight formula is most accurate?

No single formula is "most accurate" — they were all developed from population averages. The Devine formula is most widely used in medicine, but the BMI-based healthy range (18.5–24.9) is generally the most practical guide for everyday health.

Does ideal weight depend on age?

Most formulas don't account for age directly. However, research suggests older adults (65+) may do best at the higher end of the healthy BMI range, as slightly more weight is associated with better outcomes in later life.

Why do the formulas give different results?

Each formula was developed using different populations and methods — Devine (1974) for drug dosing, Robinson and Miller as refinements, and Hamwi (1964) for clinical use. The 2–4 kg spread between them shows that "ideal weight" is a range, not a single magic number.

Should muscular people use ideal weight formulas?

With caution. These formulas don't account for muscle mass, so very muscular people may healthily weigh more than their "ideal." Body fat percentage is a better guide for athletes and regular gym-goers.

How fast can I reach my ideal weight?

A safe rate is 0.25–0.5 kg per week through a modest calorie deficit of 400–500 kcal daily. Losing 10 kg takes roughly 5–10 months at this pace — slower loss is far more likely to stay off permanently.

Is my data saved when I use this calculator?

No. All calculations run entirely in your browser. Your details and results are never stored or sent anywhere.