Skip to main content
health

Ideal Body Weight Calculator (Devine)

Calculate your ideal body weight using the Devine formula. Widely used in medicine for drug dosing and clinical assessments.

Reviewed by Chase FloiedUpdated

This free online ideal body weight calculator (devine) provides instant results with no signup required. All calculations run directly in your browser — your data is never sent to a server. Enter your values below and see results update in real time as you type. Perfect for everyday calculations, homework, or professional use.

How to Use This Calculator

1

Enter your input values

Fill in all required input fields for the Ideal Body Weight Calculator (Devine). Most fields include unit selectors so you can work in your preferred unit system — metric or imperial, whichever matches your problem.

2

Review your inputs

Double-check that all values are correct and that you have selected the right units for each field. Incorrect units are the most common source of calculation errors and can produce results that are off by factors of 2, 10, or more.

3

Read the results

The Ideal Body Weight Calculator (Devine) instantly computes the output and displays results with units clearly labeled. All calculations happen in your browser — no loading time and no data sent to a server.

4

Explore parameter sensitivity

Try adjusting individual input values to see how the output changes. This is a quick and effective way to develop intuition about how different parameters influence the result and to identify which inputs have the largest effect.

Formula Reference

Ideal Body Weight Calculator (Devine) Formula

See calculator inputs for the governing equation

Variables: All variables and their units are labeled in the calculator interface above. Input fields accept values in multiple unit systems — select your preferred unit from the dropdown next to each field.

When to Use This Calculator

  • •Use the Ideal Body Weight Calculator (Devine) for personal health tracking and wellness monitoring, establishing a baseline and tracking changes over time.
  • •Use it when recording fitness metrics to track progress toward health or athletic goals.
  • •Use it to compare measurements before and after a lifestyle, diet, or training change to quantify the impact.
  • •Use it as a conversation starter before a doctor's appointment, bringing objective data to discuss with a healthcare professional.

About This Calculator

The Ideal Body Weight Calculator (Devine) is a free health and wellness calculation tool designed for personal use and general informational purposes. Calculate your ideal body weight using the Devine formula. Widely used in medicine for drug dosing and clinical assessments. This calculator provides reference values based on established health screening formulas and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Results may vary based on individual factors not captured by the calculation. Consult a qualified healthcare provider for personalized health guidance. All calculations are performed locally in your browser — no personal health data is transmitted or stored.

About Ideal Body Weight Calculator (Devine)

The Ideal Body Weight Calculator uses the Devine formula, the most widely used equation in clinical medicine for calculating a person's ideal body weight. Developed by pharmacist Ben J. Devine in 1974, this formula was originally designed for drug dosing calculations — particularly for medications where dosing based on actual body weight would be unsafe for overweight patients. Today, it's used throughout healthcare for medication dosing, nutritional assessments, ventilator settings, and clinical evaluations. Unlike BMI which gives a range of healthy weights, the Devine formula gives a single 'ideal' number. It's important to remember that this is a clinical calculation, not a fitness or aesthetic goal — real healthy weights vary significantly from person to person.

The Math Behind It

The Devine formula for ideal body weight (IBW) is primarily used in clinical medicine for medication dosing and ventilator settings, not as a weight loss target. **The Formulas**: **Men**: IBW (kg) = 50 + 2.3 × (height in inches - 60) **Women**: IBW (kg) = 45.5 + 2.3 × (height in inches - 60) For height less than 5 feet: subtract 2.3 kg for each inch below 60. **Origin of the Formula**: Ben J. Devine developed this formula in 1974 for calculating aminoglycoside antibiotic doses. It was not intended as a 'goal weight' for patients but as a way to calculate safe medication doses for overweight individuals. Other weight formulas existed but the Devine formula became dominant in clinical practice due to its simplicity. **Example Calculations**: **5'8" (68 inches) male**: IBW = 50 + 2.3 × (68 - 60) = 50 + 18.4 = 68.4 kg (150.8 lbs) **5'4" (64 inches) female**: IBW = 45.5 + 2.3 × (64 - 60) = 45.5 + 9.2 = 54.7 kg (120.6 lbs) **6'0" (72 inches) male**: IBW = 50 + 2.3 × (72 - 60) = 50 + 27.6 = 77.6 kg (171.1 lbs) **Comparison with Other Formulas**: | Formula | Men (5'10") | Women (5'5") | |---------|-------------|--------------| | Devine | 73.0 kg | 57.8 kg | | Robinson | 71.4 kg | 57.6 kg | | Miller | 68.8 kg | 55.5 kg | | Hamwi | 72.6 kg | 57.1 kg | All give similar results; Devine is most commonly used in US medicine. **Clinical Uses**: **Drug Dosing**: - **Aminoglycosides**: Gentamicin, amikacin - **Heparin**: Often based on IBW - **Vancomycin**: Uses various weight measures - **Chemotherapy**: Some drugs dose by IBW - **Anesthesia**: Some medications **Ventilator Settings**: - **Tidal volume**: 6-8 mL/kg of IBW - Applied to all intubated patients - Prevents ventilator-induced lung injury **Nutrition**: - **Enteral feeding**: Calorie targets based on IBW - **TPN**: Parenteral nutrition calculations - **Protein needs**: 1.0-1.5 g/kg IBW **Limitations and Controversies**: 1. **Gender bias**: Different formulas for men and women 2. **Height focus only**: Ignores frame size, muscle mass 3. **Race-based adjustments**: Some studies suggest different formulas for different ethnicities 4. **Not for children**: Only valid for adults 5. **Not for extreme heights**: Less accurate below 4'10" or above 7' 6. **Not a fitness target**: Clinical calculation, not personal goal **Adjusted Body Weight (AdjBW)**: For obese patients, some medications use: AdjBW = IBW + 0.4 × (actual BW - IBW) This provides a middle ground between IBW and actual weight for drug dosing. **Why Use IBW Instead of Actual Weight?** For some medications: - **Hydrophilic drugs**: Distribute only in lean mass - **Narrow therapeutic window**: Overdosing causes toxicity - **Examples**: Aminoglycosides, heparin, tidal volumes Using actual weight in obese patients would overdose them. Using IBW avoids this. **IBW vs BMI vs Body Fat %**: | Measure | Best For | |---------|----------| | IBW (Devine) | Drug dosing, ventilator settings | | BMI | Population screening | | Body fat % | Fitness assessment | | Waist circumference | Cardiovascular risk | | Waist-to-hip ratio | Metabolic risk | No single measure tells the complete story. **Pediatric IBW**: Children use different formulas (McLaren, Moore): - McLaren: Based on 50th percentile for weight at height-age - Moore: Based on 50th percentile for ideal body height These aren't covered by Devine formula. **Amputee Corrections**: For patients with amputations, IBW must be adjusted: - Hand: -0.8% - Forearm: -2.3% - Full arm: -5.0% - Foot: -1.5% - Below-knee: -5.9% - Above-knee: -11.0% - Full leg: -16.0% **Common Healthy Weight Ranges**: Using BMI 18.5-24.9 for various heights: | Height | Low (BMI 18.5) | High (BMI 24.9) | |--------|----------------|------------------| | 5'0" | 47 kg / 104 lb | 63 kg / 139 lb | | 5'4" | 54 kg / 118 lb | 72 kg / 159 lb | | 5'8" | 61 kg / 135 lb | 82 kg / 180 lb | | 6'0" | 68 kg / 151 lb | 91 kg / 200 lb | Notice: These ranges are wider than Devine IBW single values. A healthy weight could be 10-20 lbs above or below Devine IBW. **Important Note**: The Devine formula is a CLINICAL TOOL, not a personal fitness goal. Real healthy weights vary significantly based on: - Body composition (muscle vs fat) - Frame size - Body fat distribution - Age - Genetics - Activity level An athletic person may weigh 20+ pounds above Devine IBW and be perfectly healthy. Focus on overall health markers, not a single IBW number. **Criticism**: Many medical professionals criticize the widespread use of Devine formula because: 1. It's based on 1974 data 2. It doesn't reflect modern understanding of body composition 3. It's sometimes misused as a weight loss target 4. Gender-specific formulas perpetuate stereotypes Despite criticism, it remains standard for drug dosing due to simplicity and widespread adoption.

Formula Reference

Devine Formula (Men)

IBW = 50 + 2.3 × (inches over 5 ft)

Variables: For heights ≥ 5 ft

Devine Formula (Women)

IBW = 45.5 + 2.3 × (inches over 5 ft)

Variables: For heights ≥ 5 ft

Worked Examples

Example 1: Male Patient

5'10" tall male (70 inches).

Step 1:Inches over 5 ft: 70 - 60 = 10
Step 2:IBW = 50 + 2.3 × 10
Step 3:IBW = 50 + 23
Step 4:IBW = 73 kg = 160.9 lbs

Ideal body weight: 73 kg (161 lbs). This is used for medication dosing calculations, not as a target weight. Healthy weight range for this height is ~135-180 lbs.

Example 2: Female Patient

5'5" tall female (65 inches).

Step 1:Inches over 5 ft: 65 - 60 = 5
Step 2:IBW = 45.5 + 2.3 × 5
Step 3:IBW = 45.5 + 11.5
Step 4:IBW = 57 kg = 125.7 lbs

Ideal body weight: 57 kg (126 lbs). Note that women's formula starts at 45.5 kg (100 lbs) vs men's 50 kg (110 lbs) for the 5'0" baseline.

Common Mistakes & Tips

  • !Treating Devine IBW as a personal weight loss target. It's a clinical tool, not a goal.
  • !Using it for children. Only valid for adults.
  • !Applying to extreme heights. Less accurate below 4'10" or above 7'.
  • !Ignoring muscle mass. Athletic people may weigh well above IBW and be healthy.

Related Concepts

BMI Calculator

Population screening tool.

Body Fat Calculator

More accurate than weight alone.

Creatinine Clearance

Uses IBW for obese patients.

Used in These Calculators

Calculators that build on or apply the concepts from this page:

Waist-to-Hip Ratio Calculator

Frequently Asked Questions

Should I use Devine IBW as my weight loss target?

No. Devine IBW is a clinical tool for medication dosing, not a personal fitness target. Healthy weights vary significantly based on body composition, frame size, muscle mass, and other factors. An athletic person may weigh 20+ lbs above Devine IBW and be perfectly healthy. Focus on overall health markers like body fat %, fitness level, and health indicators.

Why different formulas for men and women?

Women typically have lower bone density, less muscle mass, and different body composition than men at the same height. Devine's formula from 1974 reflects these differences in typical lean body mass. Some modern researchers argue for a single formula with individual variation, but Devine's gender-specific approach remains standard in clinical practice.

How is this used in medicine?

Primarily for medication dosing. For 'hydrophilic' drugs that don't distribute into fat tissue (like aminoglycoside antibiotics), using actual body weight in obese patients would overdose them. IBW provides a safer estimate. Also used for ventilator tidal volumes (6-8 mL/kg IBW) to prevent lung injury. Clinical nutrition also uses IBW for calculating calorie/protein needs.

Is my weight unhealthy if I'm above or below Devine IBW?

Not necessarily. Healthy weight ranges are much wider than a single IBW value. Athletes often weigh well above IBW due to muscle mass. Small-framed individuals may be healthy below IBW. Focus on: BMI 18.5-24.9 range, body composition (body fat %), waist circumference (< 35" women, < 40" men), and overall health. A single weight number rarely tells the complete story.