Ideal Weight Calculator
See popular ideal body weight formulas and a healthy range for your height. Use U.S. or metric units.
How ideal weight formulas work—and how to use them well
This calculator shows several long-standing “ideal body weight” (IBW) formulas alongside a healthy weight range derived from BMI. These tools were originally designed for practical needs—dosing certain medications, estimating lung function, or setting rough targets in clinical and athletic settings—rather than defining how any particular person should look. They are quick, transparent, and good for ballpark planning, but they do not replace judgment or context about body composition, performance, or overall wellbeing.
What the formulas estimate
The four formulas shown—Robinson (1983), Miller (1983), Devine (1974), and Hamwi (1964)—express ideal weight as a base value plus an increment for every inch (or centimeter) above 5 feet. Because they were developed from different reference groups and eras, each produces a slightly different estimate. For the same height, Robinson and Miller often read lighter, Devine sits in the middle, and Hamwi trends higher. Taken together, they form a reasonable envelope that many adults will find realistic, especially when paired with a healthy BMI range.
Healthy range vs. single target
A single “ideal” number can be misleading. Two people of the same height can differ by frame size, muscle mass, training history, and genetics—while both are thriving. That’s why the calculator also translates the healthy BMI band (18.5–25) into a weight range for your exact height. If you are above the top of that band, you’ll see roughly how much weight would move you to a BMI of 25; if you are below the bottom, you’ll see the distance to a BMI of 18.5. Most sustainable plans target progress toward a band, rather than a precise number, and then refine based on how you look, feel, perform, and recover.
Interpreting results by goal
- General health: Use the BMI range as your primary guide and treat the IBW formulas as reference points. If you land near the middle of the BMI band and your labs, waist size, and daily energy are improving, you’re moving in the right direction.
- Physique or strength goals: You may aim above some formulas because extra muscle carries weight. Track body fat or waist measurements along with strength and performance to make sure weight gain is productive.
- Endurance goals: Many athletes race well near the lower half of the BMI band, but the best weight is where you can train consistently, stay healthy, and recover between sessions.
What affects a realistic personal target
- Frame size and bone structure: Broader frames often sit higher in the ranges.
- Muscle mass: Lean, muscular builds can exceed some formulas while remaining metabolically healthy.
- Age and training history: As years and responsibilities accumulate, the best target is sustainable—not extreme.
- Medical context: Work with your clinician if you have conditions that affect fluid balance, appetite, or energy use.
Turning numbers into a plan
- Pick a band (for example, midpoint of the BMI range) and set a modest weekly change—about 0.5–1 lb (0.25–0.5 kg).
- Anchor daily protein, add produce and fiber, and choose carbohydrate timing that fits your training and workday.
- Track a weekly average of weight and a waist measurement; reassess every two to three weeks.
- If progress stalls, adjust calories by ~100–200/day and keep steps and sleep consistent while you test the change.
Limitations to remember
IBW formulas and BMI do not measure body fat directly. They won’t distinguish muscle from fat, nor do they judge how you feel, sleep, or perform. They are a starting point—simple, transparent, and easy to recalculate as your situation changes. If you have a medical condition, are pregnant, or are under 20, you’ll need different tools and context than adult IBW formulas provide.
Measurement tips
- Measure height barefoot, standing tall with heels, hips, and upper back against a wall.
- Weigh at the same time of day (morning, after restroom, before eating) and average the week.
- Revisit this calculator whenever your weight shifts by a few percent or your routine changes.
Informational use only and not a medical diagnosis. If you have concerns about weight or nutrition, consult a qualified professional.
Ideal Weight Calculator — FAQ
What is an “ideal weight”?
“Ideal weight” is an estimate of a healthy body weight range for your height (and sometimes sex and frame size) based on commonly used formulas. It’s a guideline for planning, not a medical diagnosis.
Which formulas does this calculator use?
The tool can display results from several formulas (e.g., Devine, Robinson, Miller, and Hamwi). Each uses height (and sex) a bit differently, so outputs vary slightly. Showing multiple formulas gives you a reasonable range.
Is BMI the same as ideal weight?
No. BMI is a height-to-weight index; “ideal weight” formulas directly target a single weight (or range). They’re related but not identical. Many people use both for context.
How accurate are ideal weight formulas?
They are estimates. Muscularity, frame size, body composition, age, and ethnicity can shift a healthy target. Treat the result as a starting point and adjust based on your goals and health guidance.
Should I factor in frame size?
Some methods adjust targets for small/medium/large frame. If you know your frame size (e.g., wrist circumference guidelines), you can interpret the range accordingly.
Does age change the ideal weight target?
Age affects body composition and metabolic rate. Most classic formulas do not include age directly, which is why the result is a guideline instead of a prescription.
What if I’m very muscular or an athlete?
Muscle weighs more than fat at the same volume. Athletes often sit above classic “ideal” numbers while still being very healthy. Consider body-fat %, performance, and health markers in addition to weight.
Can I use inches/centimeters and pounds/kilograms?
Yes. The calculator supports both unit systems and converts behind the scenes to keep formulas consistent.
Is the output a goal weight?
It’s a planning range. Many people pick a target inside the displayed range, then refine based on progress, comfort, and clinician input.
Use cases & examples
Example 1 — 5'6" (167.6 cm)
For a person 5'6" tall, the Devine/Robinson/Miller/Hamwi formulas usually cluster within a span of a few kilos (or pounds). You might see a range roughly in the low- to mid-130s lb (≈61–64 kg), depending on the formula and sex selection. The range helps you choose a realistic target.
Example 2 — 6'0" (182.9 cm)
A 6'0" individual often lands around the mid- to high-160s lb (≈75–77 kg) with classic equations. If the person has a large frame or higher muscle mass, a slightly higher target may be more appropriate.
Example 3 — Adjusting for frame size
Suppose two people are both 5'8". One has a small frame, the other a large frame. Interpreting the result with frame size pushes the small-frame target a bit lower and the large-frame target a bit higher—without changing height. This is why we present a range and notes instead of a single “perfect” number.