Ideal Body Weight Calculator: What Should I Weigh?
Find what you should weigh for your height and sex using the four formulas doctors actually use: Devine, Robinson, Miller and Hamwi. You get a healthy range, not a single number to obsess over.
The 30-second answer
Your ideal weight depends mainly on your height and sex. The formula doctors use most is Devine: 50 kg for men or 45.5 kg for women, plus 2.3 kg for every inch above 5 feet. A 5 foot 10 inch man comes out at about 73 kg. But no single number is correct, which is why clinicians work with a healthy weight range rather than one target.
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How doctors calculate ideal body weight
The formula most clinicians reach for is Devine, published in 1974. It is deliberately simple, and it uses only two things: your height and your sex.
The Devine formula
Men: 50 kg + 2.3 kg per inch over 5 feet
Women: 45.5 kg + 2.3 kg per inch over 5 feet
Here is the arithmetic worked through for a 6 foot man. Six feet is 72 inches, which is 12 inches above 5 feet. Twelve inches times 2.3 kg is 27.6 kg. Add the 50 kg base and you get 77.6 kg. That is the whole calculation. Change your height below and watch every formula update.
Formula explorer
Change your height and sex, and watch all four medical formulas recalculate live.
Devine formula, step by step
- 1Your height in inches70.1 in
- 2Inches above 5 feet (60 in)10.1 in
- 3Multiply by 2.3 kg per inch23.2 kg
- 4Add the male base of 50 kg50 + 23.2
- Ideal body weight73.2 kg
The Devine formula is 50 kg plus 2.3 kg for every inch above 5 feet for a male. That is the equation clinicians actually use.
All four formulas compared
- Devine73.2 kg
The clinical standard, used for drug dosing.
- Robinson71.1 kg
A 1983 revision, usually reads a little lower.
- Miller70.4 kg
Rises most slowly with height, so it is lowest for tall people.
- Hamwi75.2 kg
From 1964, still common in dietetics.
They disagree by a few kilograms, and that is normal. Each was derived on a different population for a different clinical purpose. Treat the spread as a healthy range, not a contradiction.
Which ideal body weight formula is best?
None of them is best, and that is not a cop-out. Each was built on a different population for a different clinical job. Devine exists so anaesthetists can dose drugs safely. Hamwi comes from dietetics. They were never designed to tell you what to weigh in the mirror.
| Formula | Men | Women | Why it exists |
|---|---|---|---|
| Devine (1974) | 50 kg + 2.3 kg per inch over 5 ft | 45.5 kg + 2.3 kg per inch over 5 ft | The clinical standard. Used for drug dosing and ventilator settings. |
| Robinson (1983) | 52 kg + 1.9 kg per inch over 5 ft | 49 kg + 1.7 kg per inch over 5 ft | A revision of Devine. Usually reads slightly lower. |
| Miller (1983) | 56.2 kg + 1.41 kg per inch over 5 ft | 53.1 kg + 1.36 kg per inch over 5 ft | Rises most slowly with height, so it is lowest for tall people. |
| Hamwi (1964) | 48 kg + 2.7 kg per inch over 5 ft | 45.5 kg + 2.2 kg per inch over 5 ft | The oldest. Still widely used in dietetics. |
Swipe the table sideways to see every column.
Why do different calculators give different results?
Because they are not measuring you. They are applying an equation that was fitted to a group of people decades ago, and different research groups fitted different equations. For a 6 foot man, Devine says about 77.6 kg, Hamwi says roughly 80 kg, and Miller says about 73 kg. All three are correct outputs of their own formula.
The useful conclusion is not to pick a winner. It is to notice that the spread between them, usually five to seven kilograms, is the answer. Your ideal weight is a band, not a point. Anywhere inside your healthy range is a legitimate place for your body to sit.
What should I weigh for my height?
Your ideal weight depends primarily on your height and sex. Most doctors estimate it with validated formulas such as Devine, Robinson, Miller and Hamwi rather than choosing one fixed number. The table below gives both: the single Devine estimate, and the broader healthy range you should actually aim to sit inside.
Healthy weight by height
Ideal weight is a single formula estimate. The healthy range is the broader medical band you should actually aim to sit inside.
150 cm
4'11"
Healthy range42 to 56 kgIdeal weight (Devine): 43 kg
155 cm
5'1"
Healthy range44 to 60 kgIdeal weight (Devine): 48 kg
160 cm
5'3"
Healthy range47 to 64 kgIdeal weight (Devine): 52 kg
165 cm
5'5"
Healthy range50 to 68 kgIdeal weight (Devine): 57 kg
170 cm
5'7"
Healthy range53 to 72 kgIdeal weight (Devine): 61 kg
175 cm
5'9"
Healthy range57 to 76 kgIdeal weight (Devine): 66 kg
180 cm
5'11"
Healthy range60 to 81 kgIdeal weight (Devine): 70 kg
185 cm
6'1"
Healthy range63 to 85 kgIdeal weight (Devine): 75 kg
190 cm
6'3"
Healthy range67 to 90 kgIdeal weight (Devine): 80 kg
195 cm
6'5"
Healthy range70 to 95 kgIdeal weight (Devine): 84 kg
Healthy range is BMI 18.5 to 24.9 at that height. Ideal weight uses the Devine formula.
Ideal weight vs healthy weight vs target weight
These four terms get used interchangeably and they should not be. The difference matters.
Ideal weight
A formula-based estimate from your height and sex. One number, no measurement of your actual body.
Healthy weight
A broader medical range, usually BMI 18.5 to 24.9. Health outcomes are similar right across this band.
Target weight
Your personal goal. It should sit inside the healthy range, but it is a choice, not a clinical figure.
Perfect weight
Has no medical definition at all. Nobody in medicine uses this term, and no evidence supports one exact number.
Is there really a perfect body weight?
No. There is no such thing in medicine. What exists is a healthy weight range, and health outcomes are broadly similar across the whole of it. Two people of the same height can both be healthy several kilograms apart. Chasing one exact number is not supported by evidence, and it is a reliable way to make yourself miserable.
Ideal body weight vs BMI vs body fat: which should you use?
Ideal weight tells you where to aim. BMI tells you roughly where you are. Neither can tell muscle from fat, which is the thing that actually matters. Pick the tool that answers your real question.
| Tool | What it measures | Best for |
|---|---|---|
| Ideal Body Weight | A target weight from height and sex | A quick reference point for one person |
| BMI | Weight relative to height squared | Population screening, not individuals |
| Body Fat | How much of your weight is fat | Knowing your actual composition |
| Lean Body Mass | Muscle, bone, organs and water | Protecting muscle while losing fat |
Where these formulas break down
Being straight about the limits is more useful than pretending the number is precise. There are four situations where ideal body weight will actively mislead you.
Athletes and muscular people
This is the biggest blind spot. Muscle is denser than fat, so a lean, muscular person will often weigh well above their calculated ideal weight while carrying very little fat. The formula will simply call them heavy, which is useless. If you train seriously, use body fat or lean body mass instead.
Frame size
The formulas assume one skeleton for everyone of a given height. In reality a large-framed person carries more bone and lean tissue and belongs toward the top of their healthy range, while a small-framed person belongs nearer the bottom. A rough test: wrap your thumb and middle finger around the opposite wrist. Overlapping suggests a small frame, not meeting suggests a large one.
Pregnancy
Ideal body weight is not designed for pregnancy and should not be used to guide it. Weight gain in pregnancy is expected, healthy and monitored against completely different guidance. Follow your midwife or doctor, not this calculator.
Age and ethnicity
The classic formulas include neither. Body composition shifts with age as muscle falls and fat rises, and healthy body composition varies between ethnic groups, which is why some health bodies use lower BMI thresholds for people of South Asian descent. The formula stays the same, but how you read the result should not.
Using Your Ideal Body Weight as a GLP-1 Goal
If you are on a GLP-1 and looking for a finish line, the number above is a reasonable place to start the conversation. Just read it as a planning target, not a verdict.
Quick reality check on what this number actually is. Ideal body weight comes from formulas built decades ago out of height and sex, and they were designed for things like drug dosing, not for telling you exactly what your body should weigh. So treat it as a ballpark for goal setting. It is useful for pointing you in a direction, not a precise number you have to hit to the pound.
And honestly, not everyone should aim for exactly this weight. Your frame, how much muscle you carry, your age, your history, and the weight your body genuinely feels good and healthy at all matter, and none of that lives in a height-based formula. Plenty of people settle a few pounds either side of their “ideal” number and are perfectly healthy there. A weight you can hold without white-knuckling it beats a lower one you can only keep for a month. Your clinician can help you land on a target that fits you, not just the equation.
Here is the part people skip. Reaching your goal weight is not the end of the plan, it is the start of a different one. On a GLP-1 the losing phase can feel almost automatic, and then you arrive at your goal and realise nobody told you what happens next. Maintenance runs on different numbers than losing did, your maintenance calories, a protein target, and a small guardrail so a little drift does not quietly turn into a big regain. Working those out is where a proper maintenance plan comes in, and it is what actually keeps the weight off.
Reached your goal, or getting close?
Turn this target into a plan to hold it: your maintenance calories, protein, and a regain guardrail.
How we calculated this
We compute all four classic equations (Devine 1974, Robinson 1983, Miller 1983, Hamwi 1964) exactly as published, in kilograms, from your height in inches above 5 feet. The headline recommendation is the mean of the four, then pinned inside your healthy BMI band of 18.5 to 24.9 so it can never fall outside a medically sensible range. The healthy range itself is calculated from your height using the WHO BMI thresholds. We do not store your data, and nothing leaves your browser.
Sources and references
This page is built from public clinical guidance and peer-reviewed research. Always confirm decisions with a licensed clinician.
- 1.Devine BJ. Gentamicin therapy (1974), the origin of the ideal body weight formula
- 2.Pai MP, Paloucek FP. The origin of the ideal body weight equations
- 3.WHO: Body mass index and healthy weight ranges
- 4.NIH, National Heart, Lung, and Blood Institute: Assessing your weight and health risk
- 5.CDC: Assessing your weight
Medical disclaimer: Ideal body weight is an educational estimate from a formula, not a measurement of your body and not a diagnosis. It does not account for muscle mass, frame size, age or pregnancy. Always consult a qualified healthcare provider before setting a weight goal.
Common ideal weight questions
Frequently Asked Questions
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Tool Information
June 2026
Dr. Jaydeep Sanghani
Meet Akabari
Dr. Jaydeep Sanghani
MBBS, MD, DNB(Anaesth.), PDCC(CCM), DrNB(CCM)
AIIMS Bhubaneswar · AIIMS Rishikesh
Critical care specialist and anesthesiologist with advanced training from AIIMS. Reviews health calculators at Calqulate to ensure medical accuracy and evidence-based standards.
About the authors
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·Co-Founder, Calqulate.net