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Ideal Weight Calculator

Calculate your ideal weight range using 6 validated clinical formulas. Compare formulas, track your goal, and get a personalized BMI analysis.

Ideal Weight Calculator
ft in
--
Ideal Range (Avg: --)
BMI Analysis Healthy
-- AVG TARGET BMI
Under Healthy Over
Current BMI N/A
Target BMI 18.5–24.9
Ideal Wt. BMI --
Formula Comparison
Why Do These Formulas Differ?

These formulas were developed across different decades and patient populations. Hamwi (1964) was the first clinical estimate. Devine (1974) refined it for pharmaceutical use. Robinson and Miller (1983) used regression analysis. Peterson (2016) uses a modern BMI-based approach. Because each used different study populations and methods, they naturally produce slightly different results.

Ideal Weight at Adjacent Heights
HeightRobinsonMillerDevineHamwiAverage

Detailed Formula Comparison

Six established methods for estimating ideal body weight, each from a different era and methodology. Your current inputs are applied to all formulas in real time.

All Formulas at Your Height

Formula Year Result vs Average Method

Radar Comparison

Which Formula Should You Use?

Average build, general health Robinson (1983)
Conservative lower-bound estimate Miller (1983)
Pharmaceutical / clinical dosing Devine (1974)
Known small or large frame Hamwi (1964)
Modern BMI-optimized approach Peterson (2016)
Understanding your healthy range BMI-Based Range

Weight Goal Tracker

Enter your current weight and see a realistic timeline to reach your ideal range. The calculator uses your ideal weight average as the target.

lbs
lbs
-- To Lose
-- Weeks
-- Months
-- Daily Calorie Change
-- Estimated Date

Projected Weight Over Time

Calorie Deficit / Surplus Guide

0.5 lb/wk −250 kcal/day -- weeks
1 lb/wk −500 kcal/day -- weeks
1.5 lb/wk −750 kcal/day -- weeks
2 lb/wk −1000 kcal/day -- weeks

A deficit exceeding 1000 kcal/day is not recommended without medical supervision. Safe weight change is 0.5–1 lb per week for most adults.

HOW TO USE

01

Enter Your Stats

Select gender, frame size, and enter your height and age. Toggle "My Current Weight" for a personalized journey roadmap and BMI needle.

02

Compare Formulas

Switch to the Formula Comparison tab to see all 6 formulas side-by-side with a radar chart and detailed breakdowns for each method.

03

Track Your Goal

Use the Goal Tracker tab for a realistic timeline and projected weight chart. See exactly how many weeks and calories it takes to reach your ideal weight.

Expert Ideal Weight FAQ

Which ideal weight formula is most accurate?

There is no single "perfect" formula. Robinson is most cited for general populations. Hamwi is preferred when frame size is clearly small or large. Peterson (2016) is the most modern approach. Our average across all formulas provides the most balanced estimate.

How do I determine my frame size accurately?

Wrap your thumb and middle finger around your opposite wrist. If they overlap, you have a small frame. If they touch, you have a medium frame. If there is a gap, you have a large frame. Frame size adjusts your ideal weight range by approximately 10%.

Does this account for muscle mass? What is FFMI?

Standard height-based formulas do not account for muscle mass. Switch to Athletic mode and enter your body fat % to calculate your Fat-Free Mass Index (FFMI) — a far better indicator for active individuals. An FFMI of 18–20 is average, 22–24 is excellent, and 25+ is elite.

What is the Peterson (2016) formula?

Peterson et al. proposed using BMI 22 as the reference point for ideal weight: Weight (kg) = 22 × height(m)². This modern approach avoids the "inches over 60" limitation and works better for heights far from 5 ft.

Why does age matter for weight calculations?

Clinical guidelines suggest adults 65 and older benefit from a slightly higher BMI target (22–27) for longevity. For users 40+, muscle mass declines roughly 1% per year (sarcopenia). The calculator adjusts the BMI target range accordingly.

How does the Goal Tracker work?

Enter your current weight in the Goal Tracker tab. It calculates the difference to your ideal range, then shows projected weight loss/gain over time at your chosen rate. The chart visualizes your journey week by week, with estimated completion dates and daily calorie adjustments.

Can these formulas be used for children?

No. All formulas here are strictly for adults 18+. Children and adolescents should use age-and-gender-specific BMI percentile charts to track healthy development.

Is "Ideal Weight" different from "Healthy Weight"?

"Healthy Weight" refers to the broad BMI range of 18.5–24.9. "Ideal Weight" formulas attempt to find the optimal midpoint where statistical mortality risk is lowest. Our average is generally near BMI 21–22 for most adults.

Finding Your Ideal Weight

The concept of an ideal body weight has evolved significantly since the first actuarial tables were published in the 1940s. Modern clinical formulas attempt to estimate the weight at which a given height correlates with the lowest mortality risk and best overall health outcomes.

Why Six Formulas?

Each formula was developed from different populations and datasets. Robinson and Miller used updated regression analyses. Devine originally created his formula for pharmaceutical dosing. Hamwi provided the simplest rule of thumb. Peterson (2016) took a modern BMI-centered approach, and the BMI-based range shows the full healthy window. By comparing all six, you get the most complete picture of where your ideal weight lies.

Beyond the Number

Ideal weight formulas cannot distinguish between muscle and fat. A person with significant muscle mass may exceed the formula range while having excellent health markers. This is why Athletic mode uses FFMI instead. For most people, the standard mode gives a reasonable target range.

Practical Application

Use the ideal weight range as a long-term directional guide rather than a precise target. Focus on trends in body composition, energy levels, and health biomarkers. A weight that allows you to maintain consistent energy, sleep well, exercise comfortably, and sustain healthy blood markers is your personal ideal.