Ideal Weight by Height and Age: A Complete Guide with Charts
Before diving into the numbers, let's agree on something important: ideal weight is not a specific weight in grams — it's a range within which your body can function at its best. Two people of the same height may have completely different ideal weights due to age, muscle mass, and bone structure.
For this exact reason, relying on a single number from an app or website can mislead you. It's better to understand the basics, then use a tool that gives you a realistic range. Read on.
⚖️ Try the Interactive Ideal Weight Calculator ↑Why There Is No Single "Ideal Weight" for Everyone
If you asked ten doctors about the ideal weight for someone who is 170 cm tall, you'd get ten slightly different numbers. The reason is that each medical formula relies on different variables:
- Height: the primary factor in almost every formula.
- Sex: men and women differ in natural muscle and fat ratios.
- Age: after thirty, metabolism gradually slows down.
- Body frame: a broad-framed person naturally weighs more than a narrow-framed one.
- Physical activity: an athlete may be "overweight" by BMI yet have very low body fat.
Method 1: Body Mass Index (BMI)
This is the most popular and widely used method in the world, adopted by the World Health Organization. The formula is simple:
BMI = Weight (kg) ÷ (Height in meters)²
Practical example:
Suppose someone weighs 78 kg and is 1.72 m tall. Step one: square the height → 1.72 × 1.72 = 2.9584. Step two: divide weight by the result → 78 ÷ 2.9584 = 26.4. This means they fall in the "overweight" category slightly.
How to read your BMI result?
| Range | Classification |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight ✅ |
| 25 – 29.9 | Overweight |
| 30 – 34.9 | Obesity (Class I) |
| 35 – 39.9 | Obesity (Class II) |
| 40 or above | Extreme obesity |
However, BMI has well-known limitations. It doesn't distinguish between muscle and fat. A bodybuilder who is 175 cm tall and weighs 90 kg would appear in the "obese" category, while their body fat is only 8%. That's why you shouldn't rely on it alone.
Method 2: The Devine Formula
This formula was developed in 1974 for calculating medication dosages, as it gives a more accurate ideal weight than BMI. It's still referenced in medical literature today.
For men: 50 kg + 0.9 × (height in cm − 152)
For women: 45.5 kg + 0.9 × (height in cm − 152)
Calculated example:
A man who is 178 cm → 50 + 0.9 × (178 − 152) = 50 + 0.9 × 26 = 50 + 23.4 = 73.4 kg.
A woman who is 165 cm → 45.5 + 0.9 × (165 − 152) = 45.5 + 11.7 = 57.2 kg.
Ideal Weight Charts by Height
If you're looking for a quick reference, here's a table based on the healthy BMI range (18.5 to 24.9). The numbers are approximate and not a substitute for consulting a specialist.
Ideal Weight for Men
| Height | Healthy Weight Range |
|---|---|
| 155 cm | 44 – 60 kg |
| 160 cm | 47 – 64 kg |
| 165 cm | 50 – 68 kg |
| 170 cm | 53 – 72 kg |
| 175 cm | 57 – 76 kg |
| 180 cm | 60 – 81 kg |
| 185 cm | 63 – 85 kg |
| 190 cm | 67 – 90 kg |
Ideal Weight for Women
| Height | Healthy Weight Range |
|---|---|
| 150 cm | 42 – 56 kg |
| 155 cm | 44 – 60 kg |
| 160 cm | 47 – 64 kg |
| 165 cm | 50 – 68 kg |
| 170 cm | 53 – 72 kg |
| 175 cm | 57 – 76 kg |
| 180 cm | 60 – 81 kg |
Note that the difference between men and women is small in general charts, but medical formulas give slightly larger differences due to differences in body composition.
⚖️ Try the Interactive Ideal Weight Calculator ↑How Does Age Affect Your Ideal Weight?
This is a question many get wrong. The truth is that the healthy weight range for adults remains roughly constant after age twenty. What changes with age is your body composition:
- After thirty, muscle mass gradually decreases by up to 3-5% per decade.
- Basal Metabolic Rate (BMR) drops, meaning you need fewer calories to maintain the same weight.
- Fat tends to accumulate more around the abdomen, which is a risk factor even with a normal BMI.
For this reason, a 25-year-old weighing 75 kg at 175 cm might be in excellent health, while another person with the same stats at age 55 could be at risk of metabolic issues if their body fat percentage is higher.
A note on children and teenagers
Children and teenagers don't fall under these charts. They have special growth charts based on percentiles according to age and sex. Don't try to apply adult formulas to a child — they can give misleading results.
Common Mistakes When Calculating Ideal Weight
- Relying on weight alone: the scale doesn't distinguish between muscle, fat, and water. Two people of the same weight could be in completely different health states.
- Weighing at different times: weight fluctuates by 1-2 kg during the day. It's best to weigh yourself in the morning after waking up and before eating.
- Comparing yourself to others: your friend who weighs less than you isn't necessarily healthier.
- Ignoring waist circumference: belly fat is an independent risk factor. Men above 102 cm and women above 88 cm are at increased risk.
- Relying on BMI for athletes: as mentioned, athletes with large muscle mass may incorrectly appear in the "overweight" category.
Practical Steps to Reach Your Ideal Weight
Knowing your ideal weight is only the first step. The harder part is reaching it and maintaining it. Here are scientifically-proven tips:
- Don't starve yourself: crash diets fail in the long run. Aim to lose 0.5 to 1 kg per week.
- Increase protein: 1.2 to 1.6 grams per kg of body weight daily helps preserve muscle during weight loss.
- Don't neglect strength: resistance training twice a week maintains muscle and boosts metabolism.
- Sleep well: lack of sleep raises the hunger hormone (Ghrelin) and lowers the satiety hormone (Leptin).
- Drink enough water: 2 to 3 liters daily depending on your activity and weather.
- Track monthly: don't weigh yourself every day, as daily fluctuations are misleading.
Frequently Asked Questions
How do I calculate my ideal weight without a calculator?▸
Use the BMI formula: divide your weight in kilograms by your height in meters squared. If the result is between 18.5 and 24.9, you're in the healthy range. Example: weight 70 kg, height 1.72 m → 70 ÷ 2.9584 = 23.7 (normal).
Does ideal weight differ between men and women?▸
Yes, slightly. Women naturally have a slightly higher body fat percentage, and formulas like Devine give women about 4-5 kg less than men at the same height. The difference comes from differences in body composition and muscle mass.
What is the ideal weight for a 170 cm woman?▸
Based on the healthy BMI range, the range is between 53 and 72 kg. However, the most realistic range for most women at this height is 58 to 70 kg, depending on age and body frame.
What is the ideal weight for a 180 cm man?▸
Between 60 and 81 kg based on BMI. The Devine formula gives 75.4 kg as a reference number. But remember this is a range, not a fixed number.
Is BMI enough on its own?▸
No. BMI is only a preliminary indicator — it doesn't measure body fat percentage or distribution. It's best to combine it with waist circumference and body fat percentage for a fuller picture.
Can I be at a normal weight and still be unhealthy?▸
Yes, this is known as "normal weight obesity." A person may have a normal weight but a high body fat percentage and low muscle mass. That's why you should look at more than one metric.
How often should I weigh myself?▸
Once a week at the same time and under the same conditions is enough. Daily weighing may cause unnecessary anxiety due to natural fluctuations in water and food.
Conclusion
Calculating your ideal weight by height and age isn't complicated, but it requires understanding that the result is a range, not a single number. BMI is a good starting point, and formulas like Devine and Robinson give higher accuracy. More important than the number itself is your lifestyle: balanced nutrition, regular physical activity, and adequate sleep.
If you want a quick result instead of manual calculation, use the Ideal Weight Calculator which gives you the range using four formulas in seconds.
✍️ Written and published on iyadel.com — Last updated: September 2026.
