Health

Ideal Body Weight Calculator (Women)

Calculator Free · Private

Data updated: 28 abr 2026 · Source: Devine, B. J. (1974). Gentamicin therapy. Drug Intelligence & Clinical Pharmacy

Reviewed by: Martín Rodríguez (política editorial ) · Last reviewed: 28 abr 2026

Was this calculator helpful?

Finding your ideal body weight depends on multiple factors including height, frame size, and muscle composition. This calculator uses three evidence-based formulas—Devine, Robinson, and Hamwi—to estimate a healthy weight range. Each formula was developed from population studies and accounts for frame size variations. Enter your height, current weight, and frame size to compare results and understand your personalized target range.

Last reviewed: April 27, 2026 Verified by Martín Rodríguez Source: Devine, B. J. (1974). Gentamicin therapy. Drug Intelligence & Clinical Pharmacy, Robinson, J. D., et al. (1983). Resting metabolic rate and thermic effect of food. American Journal of Clinical Nutrition, Hamwi, G. J. (1964). Therapy: Changing dietary concepts. Diabetes Educator, CDC: About Adult BMI, National Heart, Lung, and Blood Institute: Classification of Overweight and Obesity by BMI 100% private

When to use this calculator

Health professionals assessing patient goals and nutritional needs
Fitness enthusiasts setting realistic weight targets based on body composition
Individuals tracking progress toward medically recommended weight ranges
Comparing multiple formulas to understand safe weight expectations
Pre-surgery or medical clearance weight benchmarking
Personal training and wellness coaching documentation

How it works

2 min read

What is ideal body weight?

Ideal body weight is the healthy weight range for an individual based on height, frame size, and body composition. For women 5'0" to 6'0" tall, it typically ranges 100–180 pounds. Healthcare providers use evidence-based formulas like Devine, Robinson, and Hamwi to calculate personalized targets that account for muscularity and bone structure variations.

How Ideal Body Weight Formulas Work

Ideal body weight (IBW) calculators estimate a healthy weight range based on height and frame size. Three major formulas are used by medical professionals:

Devine Formula (1974)

For women:
IBW (lb) = 100 + 5 × (height in inches − 60)
Frame adjustment: ±10% for small/large frames

The Devine formula is most commonly used in clinical nutrition and was derived from population studies. It accounts for approximately 50 kg (110 lb) base weight plus 2.3 kg (5 lb) per inch over 5 feet.

Robinson Formula (1983)

For women:
IBW (lb) = 49 + 1.7 × (height in inches − 60)
Frame adjustment: ±10% for small/large frames

Robinson's formula is slightly more conservative than Devine and better aligns with modern population data. It results in lower baseline weights.

Hamwi Formula (1964)

For women:
IBW (lb) = 45.5 + 2.2 × (height in inches − 60)
Frame adjustment: ±10% for small/large frames

The Hamwi formula was originally developed for diabetic patients and is still used in clinical nutrition assessments. It sits between Devine and Robinson in typical estimates.

Frame Size Adjustments

Small frame: subtract 10% from calculated weight

Medium frame: use calculated weight as-is

Large frame: add 10% to calculated weight

Frame size can be estimated by wrist circumference or skeletal structure assessment.

Worked Example

Scenario: Woman, 5'6" (66 inches), medium frame, current weight 155 lb

Devine: 100 + 5(66 − 60) = 100 + 30 = 130 lb

Robinson: 49 + 1.7(66 − 60) = 49 + 10.2 = 59.2 lb (baseline; add ~60 lb = ~119 lb)

Hamwi: 45.5 + 2.2(66 − 60) = 45.5 + 13.2 = 58.7 lb (baseline; add ~65 lb = ~124 lb)

Average: (130 + 119 + 124) ÷ 3 = 124 lb

Current BMI: 155 ÷ (66 × 0.0254)² = 25.0 (overweight category)

Ideal BMI: 18.5–24.9 range

Difference: 155 − 124 = +31 lb above average ideal

Important Limitations

No muscle vs. fat distinction: IBW formulas don't account for body composition. An athletic woman with high muscle mass may legitimately weigh more than IBW without being unhealthy.

Age not directly used: While age affects metabolism, these formulas are age-neutral. Older adults may require slightly adjusted targets.

Individual variation: Genetics, hormones, and medical conditions create significant individual differences.

Frame size subjectivity: Frame size estimation varies and is inherently subjective.

Not medical advice: Use as a screening tool only; consult healthcare providers for personalized targets.

When NOT to Use This Calculator

Pregnant or breastfeeding women (different targets apply)

Individuals with muscle-building or athletic goals (may intentionally exceed IBW)

Certain medical conditions (cancer, kidney disease) requiring modified targets)

People with eating disorder history (may require professional medical guidance)

BMI Context

Ideal body weight aligns approximately with BMI 18.5–24.9 ("normal" range). However, BMI is population-based and doesn't distinguish muscle from fat, so IBW formulas provide additional nuance.

Frequently asked questions

Which formula should I trust most?

The Devine formula is most widely used in clinical practice and nutrition counseling. However, use all three and consider the average as a realistic range. The best formula for you depends on your individual frame and body composition—discuss with your healthcare provider.

Why is my current weight above the ideal range?

Several reasons: excess body fat, higher muscle mass, medical conditions, or recent weight gain. Ideal body weight is a target range, not an absolute. A 10–20 lb difference is often normal depending on fitness level and frame size.

Can I use this if I'm very tall or very short?

Yes, but accuracy decreases at height extremes (under 4'10" or over 6'4"). These formulas were derived from average populations. For extreme heights, consult a healthcare provider.

How do I determine my frame size?

Common method: Measure wrist circumference (in inches). Small frame: <6.0", Medium: 6.0–6.5", Large: >6.5". Alternatively, assess bone structure visually. If unsure, use medium frame as default.

Is ideal body weight the same as healthy body weight?

Not exactly. Ideal body weight is an estimate from population studies. Healthy body weight is individual and depends on fitness level, muscle mass, medical history, and genetics. These formulas are useful benchmarks, not medical prescriptions.

Should I aim for the lower or upper end of the range?

Depends on your goals and current fitness. If you're sedentary, aiming for mid-range is reasonable. If you strength-train and have significant muscle, the upper end may be appropriate. Discuss with a doctor or registered dietitian.

Does age matter for ideal body weight?

Not in these formulas directly. However, metabolism typically slows with age. Older adults may benefit from slightly higher weights to maintain muscle mass. Consult your healthcare provider for age-specific guidance.

Can men use this calculator?

No, this calculator is calibrated for women. Men's ideal body weight formulas use different baseline constants. Use a men's-specific calculator for accurate results.

What if my frame size differs between assessments?

Frame size estimation has some subjectivity. If borderline between sizes, calculate both and use the resulting range. This provides a more realistic bandwidth for your target weight.

Is a 5-pound difference from the ideal significant?

No. These formulas have inherent ±5–10 lb uncertainty. Day-to-day weight varies 2–3 lb due to hydration and digestion. Focus on trends over weeks/months, not daily fluctuations.