"How much should I weigh?" is one of the most searched health questions in the world — and one of the most misunderstood. There is no single magic number for your height. There is a range, and where you sit inside that range depends on your build, your muscle mass, your age, and your overall health. This guide gives you that range, shows you exactly how it is calculated, and explains when the number matters and when it does not.
If you want your number right now, skip to our free Ideal Weight Calculator — enter your height and sex and it does the maths for you. Read on if you want to understand what that number actually means.
Why "Ideal Weight" Is a Range, Not a Single Number
Doctors and researchers stopped talking about one ideal weight decades ago, because two people of the same height can be healthy at quite different weights. A 5’8″ marathon runner and a 5’8″ weightlifter may both be fit, but the lifter will weigh considerably more because muscle is denser than fat. A small-framed person and a large-framed person of the same height will also differ, often by several kilograms.
That is why every reputable method gives you a range rather than a point. The most widely used range comes from the Body Mass Index (BMI) healthy band of 18.5 to 24.9: square your height in metres and multiply by those two numbers, and you get the weight range that keeps your BMI healthy. The classic Devine and Robinson formulas, explained below, give a single midpoint inside that range — useful as a reference point, but never a target you must hit exactly.
Height-Weight Chart: Healthy Weight by Height
The table below shows the healthy weight range for each height, based on the BMI band of 18.5 to 24.9. It applies to adults of either sex; the formulas in the next section add a sex-specific midpoint.
| Height | Healthy weight (kg) | Healthy weight (lb) |
|---|---|---|
| 5’0″ (152 cm) | 43–58 kg | 95–127 lb |
| 5’2″ (157 cm) | 46–62 kg | 101–136 lb |
| 5’4″ (163 cm) | 49–66 kg | 108–145 lb |
| 5’6″ (168 cm) | 52–70 kg | 115–154 lb |
| 5’8″ (173 cm) | 55–74 kg | 122–164 lb |
| 5’10″ (178 cm) | 59–79 kg | 129–173 lb |
| 6’0″ (183 cm) | 62–83 kg | 137–184 lb |
| 6’2″ (188 cm) | 65–88 kg | 144–194 lb |
Worked example: take someone who is 5’6″ (1.68 m). Squaring the height gives 1.68 × 1.68 = 2.82. Multiply by 18.5 for the lower end: 2.82 × 18.5 = 52.2 kg. Multiply by 24.9 for the upper end: 2.82 × 24.9 = 70.2 kg. So the healthy range is roughly 52–70 kg (115–154 lb). Anyone in that band, with normal blood pressure, blood sugar and activity levels, is in a good place weight-wise.
If your height falls between two rows, the same maths works: convert your height to metres, square it, and multiply by 18.5 and 24.9. Or let the Ideal Weight Calculator do it in seconds.
The Devine and Robinson Formulas, Explained
Two classic formulas are still widely quoted, because they were designed to give a single reference weight for a given height and sex. Both start from a base weight at 5 feet tall, then add a fixed amount for every inch above 5 feet.
The Devine Formula (1974)
- Men: 50 kg + 2.3 kg for every inch over 5 feet
- Women: 45.5 kg + 2.3 kg for every inch over 5 feet
Worked example: a woman who is 5’6″ is 6 inches over 5 feet. Her Devine weight is 45.5 + (2.3 × 6) = 45.5 + 13.8 = 59.3 kg, about 131 lb. That sits comfortably inside her 52–70 kg healthy range — as it should, since the formula was designed to land near the middle of it.
Worked example: a man who is 5’10″ is 10 inches over 5 feet. His Devine weight is 50 + (2.3 × 10) = 50 + 23 = 73 kg, about 161 lb. Again, that falls inside his 59–79 kg range, toward the upper half.
The Robinson Formula (1983)
- Men: 52 kg + 1.9 kg for every inch over 5 feet
- Women: 49 kg + 1.7 kg for every inch over 5 feet
Robinson tweaked Devine's numbers slightly after reviewing more data. For the same two people: the 5’6″ woman gets 49 + (1.7 × 6) = 49 + 10.2 = 59.2 kg (130 lb) — almost identical to Devine. The 5’10″ man gets 52 + (1.9 × 10) = 52 + 19 = 71 kg (157 lb) — 2 kg lighter than Devine.
The lesson is reassuring: two independent formulas, built years apart, agree within a kilogram or two for most people. When formulas agree that closely, you can trust the neighbourhood they point to — and stop worrying about the exact house number. For a fuller picture of how weight relates to health, see our guide to what BMI is and how to calculate it.
Ideal Weight vs BMI: Which Should You Use?
Ideal weight and BMI answer slightly different questions, and both are useful:
- Ideal weight tells you a target range in kilograms or pounds — easy to picture, easy to compare with the bathroom scale.
- BMI tells you where you stand relative to population health data — underweight (below 18.5), healthy (18.5–24.9), overweight (25–29.9), or obese (30 and above). It is the number doctors use most, because large studies link it to health risk.
They are two views of the same maths: the chart above is the BMI healthy range, expressed as weight. If you already know your BMI from our BMI Calculator, you already know whether you are inside your ideal range — a BMI between 18.5 and 24.9 means you are.
Neither measure is perfect. Both ignore muscle mass, so a muscular athlete can score as "overweight" while carrying very little body fat. Both ignore where fat sits: fat around the waist carries more health risk than fat on the hips. That is why a waist measurement, and a body fat estimate, are useful companions to the scale.
What Moves You Within the Range?
Several honest factors decide whether your healthy weight sits near the bottom, middle, or top of your range:
- Frame size. Measure your wrist: a small frame generally lands lower in the range, a large frame higher. This alone can shift the answer by 3–5 kg.
- Muscle mass. People who lift weights, play sport, or do physical work carry more muscle and weigh more at the same body fat level. That is healthy weight, not excess weight.
- Age. Adults tend to gain a little weight into middle age as muscle gives way to fat, even without eating more. A weight near the top of the range at 55 is less concerning than the same weight at 25 with a rising trend.
- Sex. On average, women carry a higher percentage of body fat than men at the same BMI, which is normal and healthy — it is why the Devine and Robinson formulas use different base weights.
- Height measurement. People often overstate their height by an inch or two. Measure yourself properly, without shoes, standing against a wall — an inch of error shifts the range by about 3 kg.
How to Use Your Number (and When to Talk to a Doctor)
Use your ideal weight range as a compass, not a verdict. If you are inside it and feel well, there is nothing to fix. If you are outside it, treat it as a prompt to look at the bigger picture — your eating patterns, activity, sleep, and trend over months — rather than a reason to crash-diet.
A few situations are worth a conversation with a doctor or dietitian rather than a calculator:
- You have gained or lost more than 5% of your body weight in six months without trying.
- You are well outside the healthy range and also have high blood pressure, high blood sugar, or a family history of heart disease or diabetes.
- You are an athlete, pregnant, over 65, or under 18 — the standard ranges were not designed for these groups and can mislead.
- You find yourself obsessing over the number. Weight is one health signal among many; if it is harming your relationship with food, that matters more than the range.
For most adults, the practical path is simple and unglamorous: eat mostly whole foods, move daily, sleep enough, and weigh yourself no more than once a week, at the same time of day. If your weight is drifting the wrong way, the fix is usually a modest calorie adjustment — our TDEE guide explains how to find your daily calorie needs — not a dramatic overhaul.
The Bottom Line
Your ideal weight is not a single number to hit; it is a range of roughly 15–20 kg for most heights, and any point inside it can be perfectly healthy. Find your range from the chart above, check the Devine or Robinson midpoint if you want a reference point, and then judge yourself by how you feel, how you move, and what your other health markers say — not by one morning's reading on the scale.
Ready for your personal number? Use our free Ideal Weight Calculator to get your range, your Devine and Robinson estimates, and your BMI in one go — no sign-up needed.
Frequently Asked Questions
What is ideal body weight?
A range, not a single number. Formulas such as Devine (1974) and Robinson (1983) estimate it from your height.
How is ideal weight calculated?
The Devine formula starts at 50 kg for men and 45.5 kg for women at 5 feet tall, then adds 2.3 kg for each additional inch of height. Robinson uses slightly different base figures.
Is ideal weight the same as a healthy weight?
Not exactly. Ideal weight is a formula estimate, while a healthy weight also depends on frame size, muscle mass, age, and body composition.
Should I use ideal weight or BMI?
They complement each other. This guide explains when each one is more useful, and why neither should be used alone.
Try it yourself: use our free Ideal Weight Calculator to get your number in seconds — no sign-up needed.