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Ideal Body Weight Calculator (Devine Formula)

Enter your height and sex to calculate your ideal body weight using the Devine formula, including a healthy range, BMI at IBW, and a Hamwi comparison.
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Luis GonzalezCreated by Luis GonzalezLast updated:

How to Use This Calculator

  1. 1

    Enter Your Height

    Input your height in inches (e.g., 70 for 5ft 10in). The Devine formula uses inches above 5 feet as its basis.

  2. 2

    Select Your Sex

    Choose 'Male' or 'Female' to apply the correct Devine formula, as the baseline weight differs between sexes.

  3. 3

    Review Your Ideal Body Weight

    Examine the calculated Ideal Body Weight in both pounds and kilograms, along with the healthy weight range and BMI at IBW.

Example Calculation

An adult male, 5ft 10in tall, wants to quickly determine his ideal body weight according to the Devine formula.

Height

70 in

Sex

Male

Results

160.9 lbs

Tips

Understand the 'Healthy Range'

The healthy weight range (IBW ± 10%) provides flexibility. It acknowledges that body composition and individual variations mean a single 'ideal' number is a guideline, not a strict target.

Consider BMI at IBW

Note your BMI at Ideal Body Weight. For most, this should fall within the 'normal weight range' (18.5-24.9 kg/m²), indicating a balanced relationship between height and weight.

Use as a Clinical Reference

The Devine formula is widely used in medical settings for drug dosing. If you are discussing medication with a healthcare provider, this calculation can provide useful context.

Estimating Your Ideal Body Weight with the Devine Formula

The Ideal Body Weight Calculator (Devine Formula) offers a precise estimate of ideal body weight (IBW) based on an individual's height and sex. Widely recognized in clinical settings, this calculator provides results in both kilograms and pounds, a healthy weight range, and even an estimated Body Mass Index (BMI) at IBW. For healthcare professionals and individuals alike, understanding this metric is crucial, especially when considering medication dosages or general health targets, with a healthy weight often falling within 10% of the calculated IBW.

The Role of Ideal Body Weight in Clinical Practice

The Devine formula is widely used by healthcare professionals for various purposes beyond general weight assessment. Specifically, it's crucial for calculating medication dosages, particularly for drugs that are highly lipid-soluble or renally cleared, where using actual body weight in obese patients could lead to overdosing. For many medications, dosages are adjusted based on IBW or an adjusted body weight (ABW), which incorporates IBW and actual weight, to ensure therapeutic efficacy and minimize toxicity. The healthy range of ±10% around IBW is often considered acceptable for general health, but precise dosing often requires the exact IBW figure.

The Devine Formula Explained for Ideal Body Weight

The Devine formula provides a straightforward method for estimating ideal body weight, with distinct calculations for males and females. It establishes a baseline weight for a 5-foot individual and then adds a specific weight increment for every inch above 60 inches (5 feet).

For Males:

IBW (kg) = 50 + 2.3 × (height in inches - 60)

For Females:

IBW (kg) = 45.5 + 2.3 × (height in inches - 60)

Once the IBW in kilograms is determined, it's easily converted to pounds by multiplying by 2.20462. This formula's simplicity and clinical utility have made it a standard reference.

💡 The Devine formula is often a component in more complex medical assessments. Our ABG Interpretation Calculator, for instance, requires accurate patient data for comprehensive analysis.

Calculating IBW for a 5ft 10in Male with Devine's Formula

Let's calculate the ideal body weight for an adult male who is 5 feet 10 inches tall:

  1. Height: 70 inches
  2. Sex: Male

Applying the Devine formula for males:

  • Inches above 5 feet = 70 - 60 = 10 inches
  • IBW (kg) = 50 + (2.3 × 10)
  • IBW (kg) = 50 + 23 = 73 kg

Converting to pounds:

  • IBW (lbs) = 73 kg × 2.20462 = 160.937 lbs

Thus, the Ideal Body Weight for a 5ft 10in male, according to the Devine formula, is approximately 160.9 lbs (73.0 kg). The calculator will also show a healthy range of 144.8–177.0 lbs (65.7–80.3 kg), and a BMI at this IBW of approximately 23.2 kg/m², which falls within the normal weight range.

💡 Understanding ideal body weight can be part of broader metabolic health goals. To explore how your body adapts to changes in energy intake, try our Adaptive Thermogenesis Estimator.

The Role of Ideal Body Weight in Clinical Practice

The Devine formula is widely used by healthcare professionals for various purposes beyond general weight assessment. Specifically, it's crucial for calculating medication dosages, particularly for drugs that are highly lipid-soluble or renally cleared, where using actual body weight in obese patients could lead to overdosing. For many medications, dosages are adjusted based on IBW or an adjusted body weight (ABW), which incorporates IBW and actual weight, to ensure therapeutic efficacy and minimize toxicity. The healthy range of ±10% around IBW is often considered acceptable for general health, but precise dosing often requires the exact IBW figure.

Origin of the Devine Ideal Body Weight Formula

The Devine formula was developed in 1974 by Dr. B.J. Devine, a pharmacist, with the primary goal of standardizing drug dosing, particularly for medications that distribute into lean body mass. Before its introduction, estimating ideal body weight was less consistent, leading to potential inaccuracies in medication administration and patient care. Dr. Devine's work provided a simple, yet effective, mathematical model that quickly gained widespread acceptance in clinical pharmacology. Its enduring use for decades highlights its utility in improving calculations for drug clearance and distribution in patients, especially in critical care environments where precise dosing is paramount, making it a cornerstone in the daily practice of countless medical professionals worldwide.

Frequently Asked Questions

What is the Devine formula for ideal body weight?

The Devine formula is a widely used calculation to estimate ideal body weight (IBW) based on height and sex. It starts with a base weight for a 5-foot person (50 kg for males, 45.5 kg for females) and adds 2.3 kg for every inch over 5 feet. Developed in 1974, it is particularly useful in clinical pharmacology for standardizing drug dosages and is frequently cited in medical literature.

Why is ideal body weight used in medicine?

Ideal body weight (IBW) is a critical metric in medicine, especially for calculating appropriate drug dosages, ventilator settings, and nutritional requirements. For patients who are significantly overweight or underweight, using actual body weight can lead to under- or overdosing of medications, impacting efficacy and safety. IBW provides a standardized reference point that helps clinicians make more precise treatment decisions.

How does the Devine formula compare to the Hamwi formula?

Both Devine and Hamwi formulas estimate ideal body weight based on height and sex, but they use slightly different coefficients, leading to variations in results. For males, Hamwi uses 106 lbs + 6 lbs/inch over 5 ft, while Devine uses 110 lbs + 5.06 lbs/inch. While Hamwi is often simpler, Devine is more commonly cited in clinical pharmacology for drug dosing due to its development context.

Does the Devine formula account for body composition?

No, the Devine formula, like most ideal body weight formulas, does not directly account for body composition (e.g., muscle mass vs. fat mass). It provides a statistical estimate of a healthy weight based on height and sex. Therefore, highly muscular individuals might have an actual weight above their calculated Devine IBW without being considered unhealthy. Clinicians often use it alongside other assessments.