Ideal Weight Calculator
How Much Should I Weigh? A Complete Guide to Ideal Body Weight, Formulas, and Health Insights
“How much should I weigh?” is one of the most commonly asked health questions. Whether for aesthetics, sports requirements, or health goals, millions chase this elusive number.
But here’s the truth: There is no single number that defines perfect weight. Your ideal weight depends on many factors, including your height, body frame size, muscle mass, age, and sex—not to mention your health status and personal goals.
In this guide, we’ll explore the science behind ideal body weight (IBW), its formulas, and practical tools to better understand what healthy really looks like for you.
1. The Origins of Ideal Body Weight (IBW)
Originally, IBW wasn’t meant to be a beauty standard. It was developed by doctors to calculate drug dosages more accurately. Later, it was adopted by the fitness world and now by health media to loosely define a person’s “ideal” range of body mass.
📌 But IBW does not consider muscle mass, fat distribution, or fitness level. So, a muscular athlete and a sedentary person with the same weight may have drastically different health profiles.
2. Why “Ideal Weight” Is a Guideline, Not a Goal
Ideal body weight formulas offer estimates, not health verdicts. You could:
Be above IBW and still healthy
Be below IBW and still thriving
Match IBW and struggle with metabolic disorders
✅ What matters more is body composition, lifestyle habits, and metabolic health.
3. Key Factors That Affect Ideal Weight
A. Age
After age 40, muscle mass typically declines
Bone density reduces, and fat distribution shifts
Regular resistance training and diet help mitigate age-related changes
B. Gender
Women naturally have more body fat
Men typically have more muscle mass and bone density
On average, men weigh more than women at the same height
C. Height
Taller individuals naturally weigh more due to higher lean mass
Muscle, bone, and organ size scale with height
D. Body Frame Size
Use wrist circumference to estimate:
Women’s Frame Size by Height
| Height | Small Bone | Medium Bone | Large Bone |
|---|---|---|---|
| <5’2″ | <5.5″ | 5.5″–5.75″ | >5.75″ |
| 5’2″–5’5″ | <6″ | 6″–6.25″ | >6.25″ |
| >5’5″ | <6.25″ | 6.25″–6.5″ | >6.5″ |
Men’s Frame Size
| Height | Small Bone | Medium Bone | Large Bone |
|---|---|---|---|
| >5’5″ | 5.5″–6.5″ | 6.5″–7.5″ | >7.5″ |
👉 Larger frames require more mass to support the skeleton, making them naturally heavier.
4. IBW Formulas: Explained with Examples
All formulas are based on a baseline weight at 5 feet of height, with additional weight added per inch above that.
A. Hamwi Formula (1964)
| Gender | Formula |
|---|---|
| Male | 48.0 kg + 2.7 kg/inch over 5 ft |
| Female | 45.5 kg + 2.2 kg/inch over 5 ft |
B. Devine Formula (1974) — Most Common
| Gender | Formula |
|---|---|
| Male | 50.0 kg + 2.3 kg/inch over 5 ft |
| Female | 45.5 kg + 2.3 kg/inch over 5 ft |
C. Robinson Formula (1983)
| Gender | Formula |
|---|---|
| Male | 52 kg + 1.9 kg/inch over 5 ft |
| Female | 49 kg + 1.7 kg/inch over 5 ft |
D. Miller Formula (1983)
| Gender | Formula |
|---|---|
| Male | 56.2 kg + 1.41 kg/inch over 5 ft |
| Female | 53.1 kg + 1.36 kg/inch over 5 ft |
Sample Calculation: Devine Formula
Height: 5’10” Male
→ 10 inches above 5 feet
IBW=50+(2.3×10)=73kg≈161lbsIBW = 50 + (2.3 \times 10) = 73 kg \approx 161 lbs
5. Ideal Body Weight Comparison Table
| Height | Devine (M) | Devine (F) | Hamwi (M) | Hamwi (F) |
|---|---|---|---|---|
| 5’0″ | 50 kg | 45.5 kg | 48 kg | 45.5 kg |
| 5’5″ | 61.5 kg | 57 kg | 61.5 kg | 56.5 kg |
| 6’0″ | 73 kg | 68.5 kg | 75 kg | 67.5 kg |
6. Using BMI to Determine a Healthy Weight
Formula:
BMI=weight(kg)height(m)2BMI = \frac{weight(kg)}{height(m)^2}
Healthy BMI range: 18.5–24.9
Example: A 6’0” person (1.83 m)
| BMI | Weight Range (kg) | Weight Range (lbs) |
|---|---|---|
| 18.5 | ~62 kg | ~136 lbs |
| 25 | ~83 kg | ~183 lbs |
7. Limitations of IBW & BMI Calculators
Ignore muscle vs fat: Muscular people may appear overweight
Don’t adjust for age, ethnicity, or sex variations
Not reliable for athletes or seniors
💡 Think of them as reference points, not health rules.
8. Healthy Weight for Children and Teens
BMI is age-adjusted and percentile-based:
| Category | BMI Percentile |
|---|---|
| Underweight | <5th |
| Healthy weight | 5th–85th |
| Overweight | 85th–95th |
| Obese | >95th |
CDC Growth Charts help assess child weight by age and gender.
9. Ideal Weight vs. Healthy Weight
| Ideal Weight (IBW) | Healthy Weight (BMI, lifestyle) |
|---|---|
| Based on height/gender | Considers diet, fitness, sleep |
| Static formula | Dynamic, personalizable |
| Good for dosage calc | Better for long-term wellness |
FAQs (Frequently Asked Questions)
Q1: Can I be healthy even if I’m above my IBW?
A: Absolutely. Many fit individuals are heavier due to muscle mass.
Q2: What’s more important—BMI or IBW?
A: Neither alone. Body composition, activity level, and metabolic health matter more.
Q3: What if I’m below my IBW?
A: It’s okay if you’re energetic and not undernourished. Talk to a healthcare provider if unsure.
Q4: Should I track my weight or body fat?
A: Body fat is more revealing. Use smart scales or calipers to monitor fat %.
Q5: How do I determine my frame size?
A: Measure your wrist and compare it to the frame size charts above.
Q6: Is the Devine formula the best one?
A: It’s the most popular, but use it alongside BMI, lifestyle, and clinical inputs.
Health First, Not the Scale
Your weight is just a number—it doesn’t define your health, self-worth, or capabilities. While IBW and BMI offer useful reference points, what really matters is:
Balanced nutrition
Regular movement
Positive mental health
Adequate sleep
Active self-care
💡 Use the formulas to guide you, but listen to your body, talk to professionals, and focus on long-term wellbeing—not numbers.