Ideal Weight Calculator

What Is an Ideal Weight Calculator?

An ideal weight calculator is a free health tool that estimates a healthy target weight based on your height and sex using the Devine formula, a formula originally developed for clinical use. This ideal weight calculator provides a simple reference point�not a strict goal�for understanding what a healthy weight might look like for your frame. Unlike a free BMI calculator which gives a range, the Devine formula offers a single estimate based on the assumption that taller people should weigh more. Use this ideal weight calculator as one data point among many (alongside your body composition, fitness level, and overall health), not as an absolute target to chase.

How to Use This Ideal Weight Calculator

1. Select your sex: Choose Male or Female, since the Devine formula uses different starting weights for each.
2. Choose your unit system: Select either US Units (feet and inches) or Metric Units (centimeters).
3. Enter your height: Input your exact height in the selected units.
4. View your estimated ideal weight instantly: The calculator displays your ideal weight according to the Devine formula in either pounds or kilograms depending on your unit choice.
5. Understand it's one reference point: Remember this is an estimate that doesn't account for muscle mass, frame size, or bone density�factors that affect healthy weight individually.

Key Features of This Ideal Weight Calculator

• Uses the Devine formula, a widely recognized clinical reference (created in 1974)
• Supports both US units (pounds and feet/inches) and metric units (kilograms and centimeters)
• Provides a quick estimate based on height and sex only
• Free and simple�no signup or hidden calculations
• Useful as a health reference point to discuss with a doctor or dietitian
• Completely private�all calculations happen in your browser, no data is sent anywhere
• Clear disclaimer that this is a general estimate, not a medical goal

Real-World Ideal Weight Calculator Scenarios

Scenario 1: Comparing Weight Loss Goals
A 5'10" woman weighs 185 lbs with a BMI of 26.5 (overweight). Her ideal weight estimate from this calculator is 139 lbs, giving her a concrete number to work toward. However, if she's athletic with significant muscle mass, 155 lbs might be healthier for her specific body composition than the ideal weight estimate�which is why she should discuss the goal with her doctor.

Scenario 2: Medical Dosage Calculation
A clinician uses this ideal weight calculator to estimate a patient's lean body weight for determining safe medication dosages. This is the calculator's original purpose�knowing approximate lean weight helps ensure drugs dosed per kilogram of body weight aren't over- or under-dosed for larger patients.

Scenario 3: Post-Surgery Recovery Target
After weight loss surgery, a patient uses this ideal weight calculator as one benchmark in their recovery journey, alongside regular check-ins with their bariatric team. The number provides a target range but isn't inflexible�the goal is sustainable health, not hitting a specific number.

How ideal weight is calculated

This calculator uses the Devine formula: for men, it starts at 50 kg for exactly 5 feet of height and adds 2.3 kg for every inch over that; for women, it starts at 45.5 kg with the same 2.3 kg per inch. It's a purely height-based formula it doesn't ask about frame size, muscle mass, or age, which keeps it simple but also limits how personalized the result can be.

A formula built for a different purpose

The Devine formula wasn't originally created as a wellness benchmark. Dr. B.J. Devine published it in 1974 as a quick way for clinicians to estimate lean body weight for calculating safe medication dosages some drugs are dosed relative to lean mass rather than total body weight, and actual weight can be misleading for that purpose. It was adopted more broadly as a general "ideal weight" reference over the following decades, which is a repurposing of the formula rather than its original intent.

It's one of several competing formulas

Devine isn't the only ideal-weight formula in use. The Robinson formula (1983), the Miller formula (1983), and the older Hamwi formula (1964) all calculate a similar starting-weight-plus-per-inch estimate, but with different constants so plugging the same height into each one produces a noticeably different number. None of them is more "correct" than the others; they're all rough population-based approximations.

Is this a strict target?

No. "Ideal weight" formulas are rough estimates that don't account for muscle mass, frame size, or body composition. A muscular or large-framed person may naturally weigh more than this estimate while still being perfectly healthy, and this is a general estimate, not medical advice. Use it as a reference point to discuss with a doctor or registered dietitian, not a number to chase on its own.

FAQ

Why does this differ from BMI-based healthy weight ranges?
Different formulas use different assumptions. The Devine formula gives a single reference point, while BMI gives a healthy range both are estimates, not precise targets.

Does this apply to children?
No this calculator is intended for adults. Children's healthy weight is assessed differently using growth charts.

Why do other ideal weight calculators give me a different number?
Several competing formulas exist Devine, Robinson, Miller, and Hamwi are the most common and each uses slightly different starting weights and per-inch adjustments, so results can vary by several pounds depending on which one a calculator uses.

Was this formula originally designed for general health?
No. The Devine formula was created in 1974 specifically to help clinicians estimate a patient's lean body weight for calculating safe medication doses, particularly for drugs where dosing by actual body weight could be inaccurate for larger patients. Its use as a general "ideal weight" reference came later.

Does this account for muscle or frame size?
No. The formula only uses height and sex, so it can't account for a naturally larger or smaller frame, muscle mass, or bone density all of which affect what a healthy weight looks like for a specific individual.

What should I do with this number?
Treat it as one data point among many, not a goal to chase. A doctor or registered dietitian can help interpret it alongside your body composition, health history, and personal goals.

Related Body Measurement Tools

Understanding your ideal weight is part of a complete health picture. Our free bra size calculator uses similar measurement techniques to help you find your correct sizing with precision and confidence.