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What is Ideal Body Weight?

Ideal body weight is the most proportional and healthy body weight for a person based on their height. Knowing your ideal weight is very important for maintaining long-term health, preventing chronic diseases, and optimizing physical performance. In Indonesia, people often use the simple Broca formula: ideal weight = (Height - 100) - certain percentage. However, medical professionals more frequently use the Devine or Robinson formulas which have been clinically validated. Kalkulab's Ideal Weight Calculator provides three calculation methods at once: Broca formula (classic), Devine formula (medical standard), and BMI-based formula (WHO standard). Each method gives slightly different results because they use different approaches. You can compare all three results to get a more comprehensive picture of your ideal weight target.

Ideal Weight Formula

Broca: Ideal Weight = (H - 100) - 10% (men) or 15% (women)

Variables:

  • BrocaH - 100, then subtract %
    H - 100, then subtract %(e.g.: (170-100) - 7 = 63 kg)
  • Devine50 + 0.9×(H-152) cm (men)
    50 + 0.9×(H-152) cm (men)(e.g.: 50 + 0.9×18 = 66.2 kg)
  • BMI-basedBMI 22 × H² (m)
    BMI 22 × H² (m)(e.g.: 22 × 1.7² = 63.6 kg)

Categories:

< 18.5Underweight
18.5 - 22.9Normal - Ideal
23.0 - 24.9Normal - Upper
25.0 - 29.9Overweight
≥ 30.0Obesity

How to Use the KalkuLab Ideal Weight Calculator

  1. 1

    Enter Height

    Enter height in centimeters (cm). Measure without shoes, standing straight.

  2. 2

    Select Gender

    Select male or female—the Broca formula uses different percentage adjustments (10% vs 15%).

  3. 3

    Select Formula (Optional)

    By default all formulas are shown. You can focus on Broca, Devine, or BMI-based.

  4. 4

    View Results & Healthy Range

    See ideal weight from each formula plus healthy BMI range (18.5–25) for reference.

Examples

Example 1: Adult Male Starting Fitness

Problem:

John (28), 175 cm, currently 176 lb. What is his ideal weight target?

Solution:
  1. 1.Broca: ~149 lb
  2. 2.Devine: ~156 lb
  3. 3.BMI-based: ~149 lb
  4. 4.Healthy range BMI 18.5–25: 125–168 lb
Result:~149–156 lb (healthy range 125–168 lb)

John can target ~154 lb. At 176 lb he needs to lose about 22 lb through diet and exercise.

Example 2: Woman Planning a Healthy Diet

Problem:

Sarah (35), 160 cm, 150 lb. What is her ideal weight?

Solution:
  1. 1.Broca (female): ~112 lb
  2. 2.Devine: ~116 lb
  3. 3.BMI-based: ~124 lb
  4. 4.Healthy range: 103–141 lb
Result:~112–124 lb

Sarah can target ~121 lb (BMI 21.5). Gradual loss of 1–2 lb per week is recommended.

Example 3: Underweight Student

Problem:

Mike (20), 172 cm, 115 lb. Wants to gain weight.

Solution:
  1. 1.Broca: ~143 lb
  2. 2.Devine: ~150 lb
  3. 3.BMI-based: ~143 lb
Result:~143–150 lb

Mike should gain about 28 lb through nutritious eating, high protein, and strength training.

Example 4: Muscular Athlete

Problem:

Alex (25), 170 cm, 172 lb, 10% body fat. Is he overweight?

Solution:
  1. 1.BMI = 27.0 (overweight category)
  2. 2.Broca ideal: ~139 lb
  3. 3.High muscle mass makes BMI misleading
Result:BMI 27 but healthy

Use body fat % rather than BMI/ideal weight for athletic builds.

Example 5: Healthy Senior

Problem:

Robert (70), 165 cm, 137 lb. How is his weight for his age?

Solution:
  1. 1.Broca: ~129 lb
  2. 2.Current BMI = 22.8 (normal)
  3. 3.Senior target BMI 22–26
Result:137 lb (BMI 22.8) — Healthy

Robert's weight is excellent for his age; no diet needed.

Frequently Asked Questions

Which formula is most accurate?
No formula is perfect. Broca is easy to remember; Devine and BMI-based (target BMI 22) are more clinically validated. What matters most is staying in a healthy BMI range (18.5–25).
What is the difference between ideal weight and healthy weight?
Ideal weight is a specific target (e.g., 143 lb). Healthy weight is a range (BMI 18.5–25). You do not need to hit the exact ideal number—staying in the healthy range is sufficient.
Why do formulas differ for men and women?
Men typically have more muscle mass; women have higher essential body fat. Ideal weight for men is usually 10–15 lb heavier at the same height.
Do these formulas apply to children and teens?
These formulas are for adults (18+). Children use WHO growth charts by age. Consult a pediatrician for child weight evaluation.
What about athletes with high muscle mass?
Ideal weight formulas can underestimate muscular athletes. Use body fat percentage as the primary indicator instead.
Does ideal weight change with age?
Yes—muscle tends to decrease and fat increases with age. For seniors (60+), a slightly higher BMI target (22–26) may be appropriate.
How can I reach ideal weight safely?
To lose weight: 300–500 kcal daily deficit, cardio + strength training 3–4×/week, protein 1.6–2 g/kg. To gain weight: 300–500 kcal surplus, strength training, high protein and complex carbs.
Can I calculate ideal weight without a calculator?
Yes—Broca: (height cm − 100) minus 10% (men) or 15% (women). Example: 160 cm woman → 60 − 9 = 51 kg. Use our calculator to compare multiple formulas at once.

Related Calculators

BMI Calculator

Body mass index

Body Fat Calculator

Body fat percentage

Calorie Calculator

Daily calorie needs (TDEE)

BMR Calculator

Basal metabolic rate

Macronutrient Calculator

Daily protein, carbs, fat

References