Ideal Weight Calculator
Estimate a broad healthy weight range from your height using UK-friendly units, then compare it with a formula-based ideal weight estimate.
Calculate an estimated healthy weight range
Enter your height. The result shows a broad adult BMI-based range plus one formula estimate for comparison.
What this calculator means
This calculator turns height into a broad adult weight range using the common healthy BMI band. It also shows a separate formula estimate so you can see why “ideal weight” calculators often produce a single number.
The range is usually more useful than one number. People with the same height can have different healthy weights because of muscle, frame size, age, health history, body composition and activity level.
Ideal weight formula
The calculator shows two different views: a healthy BMI weight range and a formula-based estimate. These are planning estimates, not targets.
Healthy lower weight = 18.5 × height in metres²
Healthy upper weight = 24.9 × height in metres²
Devine estimate for men = 50kg + 2.3kg for each inch over 5ft
Devine estimate for women = 45.5kg + 2.3kg for each inch over 5ftThe BMI range gives a wider band. The formula estimate is narrower and should be treated with caution, especially for very short, very tall, highly muscular or medically complex people.
Healthy range vs target weight
A healthy range is not the same as a personal target. A personal target may need to consider current weight, waist measurement, eating habits, activity, medical history, medication, pregnancy status and professional advice.
| Output | What it is | How to use it |
|---|---|---|
| Healthy BMI range | A broad range based on height | Use it as context, not a command. |
| Formula estimate | A height-based single-number estimate | Compare it, but do not treat it as perfect. |
| Current body composition | Muscle, fat and waist distribution | Use alongside BMI-style results for a fuller picture. |
When ideal weight estimates can be misleading
Ideal weight calculators can be misleading when they make a single number feel more precise than it is. They do not directly measure body fat, muscle, fitness, diet quality, sleep, medical conditions or wellbeing.
- High muscle mass: strength-trained people may weigh more without having excess body fat.
- Pregnancy: weight ranges need pregnancy-specific advice.
- Children and teenagers: adult BMI ranges should not be used.
- Eating disorder concerns: weight calculators can be harmful or distressing.
- Medical conditions: fluid retention, medication and disability can change interpretation.
For more context, compare this with the Body Fat Percentage Calculator and the BMI Calculator.
Worked examples
What to do with the result
Use the number as context, not a rule. If your result worries you, or if you are thinking about a major weight change, it is better to speak to a GP, dietitian or qualified professional than rely on a calculator alone.
If you are simply trying to understand your body metrics, the next useful tools are calorie needs, protein intake and body fat percentage estimates.
Ideal weight calculator FAQs
Is there one ideal weight for my height?
No. A calculator can estimate a broad range, but there is no single perfect number that applies to everyone.
How is the healthy weight range calculated?
It uses the common adult healthy BMI range of 18.5 to 24.9 and converts that into a weight range for your height.
Why does the formula estimate differ from the BMI range?
The formula estimate is a single height-based calculation. The BMI range is broader, which is usually more realistic for everyday use.
Should I aim for the midpoint?
Not necessarily. The midpoint is only a mathematical reference. Your healthiest weight may be above or below it.
Sources and safety notes
This page uses common adult BMI range calculations and a height-based formula estimate. For wider context, see the NHS adult BMI calculator, NICE guidance on BMI and waist measurement, and a clinical explanation of ideal body weight formulas.
Calculatorz pages are for general information only and are not medical advice.