Mealiv
Ideal Weight Calculator
Estimate a healthy weight range for your height, and compare four established ideal-body-weight formulas.
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Enter your height to see a healthy weight range in kilograms, pounds and stones, along with what the traditional formulas estimate.
No single formula can tell you your healthiest weight. Body composition, waist measurement, muscle mass, age and your own health history all matter, and none of them fit in an equation that only knows how tall you are.
Your estimated healthy weight range
This corresponds to an adult BMI of 18.5 to 24.9. It is a general screening range, not a personalised medical target — muscle mass, body composition, waist measurement and your own health circumstances all affect what is appropriate for you. The midpoint is —, shown for reference only. There is nothing better about the middle of the range than either end.
What the traditional formulas estimate
Estimate a realistic goal dateWhat is an "ideal weight"?
Usually it means an estimated body weight considered appropriate for someone's height. The trouble is that no single weight is correct for everyone of the same height.
Two people can share a height and a weight while differing completely in muscle mass, body-fat percentage, waist measurement, bone structure, fitness and health history. One might be an athlete and the other sedentary, and the scales cannot tell them apart.
That is why a range is more useful than a target, and why this page leads with one.
How the healthy range is calculated
By reversing the BMI formula. BMI is weight in kilograms divided by height in metres squared, so multiplying a BMI back by height squared gives the weight that would produce it.
lower = 18.5 × height² upper = 24.9 × height²
For someone 1.75m tall:
18.5 × 1.75² = 56.7kg 24.9 × 1.75² = 76.3kg
So the estimated healthy range is roughly 56.7kg to 76.3kg — a spread of nearly 20kg, which is worth noticing. "Healthy weight" is a broad territory, not a point.
The four traditional formulas
Each adds a fixed amount per inch above five feet to a sex-specific base weight. They differ in both numbers, which is why they disagree.
| Formula | Male | Female | Origin |
|---|---|---|---|
| Devine (1974) | 50kg + 2.3kg/inch | 45.5kg + 2.3kg/inch | Drug dosage calculations |
| Robinson (1983) | 52kg + 1.9kg/inch | 49kg + 1.7kg/inch | A revision of Devine |
| Miller (1983) | 56.2kg + 1.41kg/inch | 53.1kg + 1.36kg/inch | Higher base, smaller increment |
| Hamwi (1964) | 48kg + 2.7kg/inch | 45.5kg + 2.2kg/inch | Estimating needs in diabetes care |
None was designed as a weight-loss target. Devine in particular was built to calculate drug doses, and has been quoted as a body-image benchmark ever since by people who have never read the paper.
Why they disagree
Different base weights, different per-inch increments, different research populations, different original purposes. At most heights they land several kilograms apart, and the gap widens the further you are from five feet.
That disagreement is genuinely informative. If four published equations built by clinicians cannot settle on one number, no single figure deserves to be treated as the weight you ought to be.
Is the BMI range more useful?
For most adults, yes — it is a range rather than a point, and it comes with categories that are widely understood:
| BMI | Category |
|---|---|
| Below 18.5 | Underweight range |
| 18.5 – 24.9 | Healthy weight range |
| 25 – 29.9 | Overweight range |
| 30 and above | Obesity range |
It is still a screening measure, not a diagnosis. It cannot distinguish muscle from fat, see where fat is stored, or account for bone mass or fitness. Someone carrying significant muscle can sit above the range with low body fat. Our BMI calculator covers those limits in more depth.
Does ethnicity change the thresholds?
Yes, and it is a meaningful difference rather than a footnote.
The standard BMI bands were derived largely from white European populations. Some UK guidance applies lower thresholds for people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds, because weight-related conditions such as type 2 diabetes develop at lower BMIs: increased risk from 23, higher risk from 27.5.
You can switch the calculator between the two. It will tell you which set it is using rather than changing the range quietly — and the formula estimates stay the same either way, because they do not use ethnicity at all.
Is your ideal weight the same as your goal weight?
Usually not, and conflating them is how people set themselves an unreachable first target.
A useful goal weight is realistic, sustainable, compatible with eating well, and reviewed as you go. Someone starting well above the range is generally better served by an interim target than by aiming straight at the bottom of it.
Losing 5–10% of your starting weight is the usual first milestone, and it delivers most of the measurable health benefit — improvements in blood pressure, blood glucose and cholesterol arrive well before any particular BMI does. The weight loss calculator turns a chosen target into a timeline and a daily calorie figure.
Should you aim for the middle?
No. The midpoint has no special status — it is just arithmetic on the two ends.
Where you sit most comfortably within a healthy range depends on muscle mass, fat distribution, age, health history, what you enjoy, what you are training for, and above all what you can maintain without it occupying your thinking.
What else is worth measuring?
Waist-to-height ratio
NHS guidance recommends this alongside BMI for adults with a BMI under 35. The rule of thumb is straightforward: keep your waist under half your height. It captures abdominal fat, which BMI cannot see and which carries more metabolic risk than fat stored elsewhere.
Body-fat percentage
More informative than total weight, particularly for anyone with above-average muscle. The body fat calculator estimates it from tape measurements.
The trend, not the reading
One measurement on one morning tells you very little. A direction of travel over months tells you almost everything.
What affects a healthy body weight?
Height is the obvious one, and the only input these formulas really use.
Muscle mass adds weight without adding fat, which can push someone above a BMI range while being in excellent health.
Fat distribution matters more than total amount — abdominal fat carries different implications from fat stored on the hips and thighs.
Age changes body composition even when weight holds steady.
Genetics shape frame, build and where fat is stored.
Health conditions and medication affect appetite, fluid retention and activity, sometimes substantially.
Pregnancy makes this kind of calculator inappropriate entirely.
Who should not rely on this
It is a general guide for adults. It is not a suitable personal target for anyone under 18, anyone pregnant, elite or highly muscular athletes, anyone with an eating disorder or a history of disordered eating, anyone with a condition significantly affecting weight or fluid balance, or anyone already receiving individual weight-management advice from a clinician.
In all of those situations a general online formula is the wrong tool, and personal professional guidance is the right one.
Moving towards a healthy weight
A calculator gives context. Habits give results. The ones with the best evidence behind them are unremarkable: a moderate calorie deficit where weight loss is appropriate, enough protein, plenty of fibre, planned meals, sensible portions, daily activity, resistance training, consistent sleep, and reviewing progress over weeks rather than days.
Mealiv turns a chosen target into daily calorie and macro goals, builds meal plans around them, tracks what you eat, and adjusts as your weight changes. Start with the weight loss calculator if you have a target in mind, or the calorie calculator if you do not yet.
How this is calculated
The healthy range reverses the BMI formula, multiplying a BMI of 18.5 and 24.9 by height in metres squared. The adjusted option uses an upper threshold of 22.9, following UK guidance for several ethnic groups, and states clearly when it is in use. The four formula estimates add a per-inch increment above five feet to a sex-specific base: Devine (50/45.5 + 2.3), Robinson (52 + 1.9 / 49 + 1.7), Miller (56.2 + 1.41 / 53.1 + 1.36) and Hamwi (48 + 2.7 / 45.5 + 2.2). Current weight, when supplied, is compared with the range and never used to change it. These are general screening estimates for adults, not medical targets.
healthy range = BMI × height²
Sources
Frequently asked questions
What is my ideal weight?
There isn't one exact figure. This page gives a BMI-based healthy range for your height and shows what four traditional formulas estimate, which are best read as context rather than as targets.
How is ideal weight calculated?
The range reverses the BMI formula — a BMI of 18.5 and 24.9 multiplied by your height in metres squared. The formulas add a fixed weight per inch above five feet to a sex-specific base.
What is a healthy weight for my height?
Whatever falls between those two BMI figures for your height — often a spread of 15 to 25kg. It is a screening guide and may not suit every body type.
Which formula is most accurate?
None, individually. They use only height and sex, ignoring muscle mass, body composition and waist measurement. The size of the gap between them is the honest answer to how precise any of them can be.
Should I use the Devine formula?
As a reference point, yes. As a goal, no — it was developed in 1974 for calculating drug doses, not for deciding what anyone should weigh.
Is ideal weight based on age?
The four formulas do not use age at all. Age still affects body composition and what is realistic, which is one of several things these equations cannot see.
Does it differ for men and women?
The formulas use sex-specific constants, so their estimates differ. The BMI range is calculated from height alone and is identical for anyone of that height.
Can muscular people use this?
You can view it, but BMI-based ranges are less representative if you carry significant muscle — you may sit above the range with low body fat. Body-fat percentage and waist measurement give better context.
Should I aim for the bottom of the range?
No. There is no benefit to the lower end over the middle or upper end. The right place within it depends on your build, your health and what you can maintain comfortably.
How much should I lose first?
If you are above the range, 5–10% of your current weight is a more practical first milestone than the range itself — and it delivers most of the measurable health benefit.
Is it suitable during pregnancy?
No. Weight change in pregnancy is expected and should be discussed with a midwife or GP.
Can children use it?
No. Children and teenagers need age- and sex-specific growth assessments, not adult BMI ranges.
Turn a target into a plan
Pick a realistic goal, then let Mealiv work out the calories, the macros and the meals to get there.
Build meals around my goalImportant information
These are general screening estimates for adults and are not medical advice or a personal weight target. The calculator cannot judge what weight is appropriate for you. It is not suitable for anyone under 18, during pregnancy, for highly muscular athletes, or for anyone with a condition significantly affecting weight or fluid balance. Speak with a GP or registered dietitian for individual guidance. If thinking about your weight is affecting your wellbeing, Beat runs a free confidential helpline.