Free ideal-weight calculator

Estimate a healthy weight range without pretending there is one magic number.

This calculator blends Devine, Robinson, Miller, and Hamwi into a calmer range based on height, sex, and frame size. Use it to build a more realistic scale target, then follow it with BMI, body-fat, and calorie planning before making big decisions.

Start the calculatorAdd body-fat context

Best use case

Turning “what should I weigh?” into a useful range instead of a rigid demand.

Biggest caveat

Ideal weight still cannot see muscle mass, fat distribution, or why your weight is what it is.

Best follow-up

BMI, body fat, and maintenance calories are the fastest ways to turn the range into a real plan.

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Ideal weight calculator

Build a healthy-weight range, not one rigid number.

This tool blends four common ideal-weight formulas, adjusts the answer by frame size, and lets you compare an optional current weight against the selected range.

Example presets
cm
kg

Add this only if you want the calculator to show how far below or above the selected range you currently sit.

Start with height and frame size.

The calculator blends Devine, Robinson, Miller, and Hamwi into a healthier range target. Add current weight if you want an immediate comparison against that range.

How to use the range without letting the range use you

The point of ideal weight is not to give you a perfect identity score. The point is to make your next decision calmer: stay where you are, move slowly up, or move slowly down.

Use ideal weight as a planning band

Ideal-weight formulas are best used to define a neighborhood you may want to live in, not one exact number you have to force.

Compare it with body composition

If you train hard, carry more muscle, or have an unusual build, body-fat and waist data matter more than the formula average.

Only make calorie changes after that

Once the range makes sense, move into maintenance calories, a moderate deficit, or a steady gain phase instead of reacting emotionally to the scale.

Check trends, not one weigh-in

Daily weight noise can make you overreact. Use weekly trend data when deciding whether you are moving toward or away from the range.

Why four formulas are better than one

Formula choice alone can move the answer. Showing several of them side by side is more honest than pretending the selected formula is perfect.

Devine

1974

The most common clinical reference and the formula many people mean when they say ideal body weight.

Best when you want the most familiar clinical baseline.

Robinson

1983

A lighter modification that often softens the target compared with Devine, especially for shorter people.

Useful when you want a less aggressive midpoint.

Miller

1983

Another revision that tends to land near the middle of the pack and helps keep the blended result from leaning too heavily on one formula.

Useful as part of the consensus range rather than as a solo answer.

Hamwi

1964

An older clinical rule of thumb that still helps show how much formula selection alone can move the answer.

Best viewed as a comparison point, not a single truth.

A blended range is especially helpful if you are tempted to force weight changes aggressively. The disagreement between formulas is a reminder that the target is approximate by design.

Frame size should adjust the answer, not dominate it

Frame size is there to stop a narrow or broad skeletal build from being forced into the same exact scale target. It should shift the range sensibly, not justify any number you want.

Small frame

Usually fits narrower wrists, shoulders, and a lighter skeletal build. The range should sit below the medium-frame midpoint, not drastically below it.

Medium frame

The safest default if you are unsure. It gives you a solid middle band before you decide whether your build clearly belongs elsewhere.

Large frame

Appropriate when your skeletal build is obviously broader and you naturally carry more scale weight before body fat becomes the issue.

If you are unsure, use medium frame first. Then cross-check the result with BMI, body-fat, waist, and how you actually look and perform. That sequence is safer than trying to self-justify a large frame because it makes the target more comfortable.

Frequently Asked Questions

What is ideal body weight really used for?

It is mainly a reference estimate. Clinicians use it for rough assessment and sometimes dosing context, while everyday users can use it as a planning range for healthier scale expectations.

Is ideal weight more useful than BMI?

Neither is complete by itself. BMI is faster for screening. Ideal-weight formulas give a more direct scale target. Both still need body-composition, waist, training, and health context.

Should I try to hit the exact midpoint?

Usually no. The midpoint is just a convenient summary. If your habits, performance, body composition, and health markers look better slightly above or below it, that matters more.

Why do different formulas disagree?

Because they were created in different contexts and use slightly different assumptions about how height maps to weight. The disagreement is the reason a range is more honest than one hard target.

What should I check after this calculator?

BMI, body-fat estimates, waist measurements, and maintenance calories are the most useful next steps because they tell you whether changing weight is actually the right move.

Research and reference notes

1. Pai and Paloucek (2000) The Origin of the "Ideal" Body Weight Equations

Review of how common ideal-body-weight formulas originated and where they are still used.

2. Variability in Ideal Body Weight Formulae and Their Use in Clinical Practice (2023)

Recent paper highlighting the spread between formulas and the caution needed when treating any one of them as exact.

3. CDC: About Adult BMI

Public-health background on BMI and why simple weight metrics still need interpretation.

4. NHLBI: Assessing Your Weight and Health Risk

Broader public-health guidance on weight, waist, and overall health-risk context.