There is no single "ideal" weight for everyone. This guide explains different methods for calculating a healthy weight range based on your height, build, and other factors.
BMI Healthy Weight Range
A healthy BMI is between 18.5 and 24.9. This gives a range of weights for each height.
Healthy Weight by Height (BMI 18.5-24.9)
| Height | Min Weight | Max Weight |
|---|---|---|
| 5ft 0in (152cm) | 43 kg (6st 11lb) | 58 kg (9st 2lb) |
| 5ft 4in (163cm) | 49 kg (7st 10lb) | 66 kg (10st 5lb) |
| 5ft 8in (173cm) | 55 kg (8st 9lb) | 75 kg (11st 11lb) |
| 6ft 0in (183cm) | 62 kg (9st 11lb) | 84 kg (13st 3lb) |
| 6ft 2in (188cm) | 65 kg (10st 3lb) | 89 kg (14st 0lb) |
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Ideal Weight Formulas
Devine Formula (Most Common)
For Men:
50 kg + 2.3 kg for each inch over 5 feet
For Women:
45.5 kg + 2.3 kg for each inch over 5 feet
Robinson Formula
Men: 52 kg + 1.9 kg per inch over 5ft
Women: 49 kg + 1.7 kg per inch over 5ft
Miller Formula
Men: 56.2 kg + 1.41 kg per inch over 5ft
Women: 53.1 kg + 1.36 kg per inch over 5ft
Comparison by Height (Men)
| Height | Devine | Robinson | Miller |
|---|---|---|---|
| 5ft 6in | 63.8 kg | 63.4 kg | 64.7 kg |
| 5ft 10in | 73.0 kg | 71.0 kg | 70.3 kg |
| 6ft 0in | 77.6 kg | 74.8 kg | 73.1 kg |
Comparison by Height (Women)
| Height | Devine | Robinson | Miller |
|---|---|---|---|
| 5ft 2in | 50.1 kg | 52.4 kg | 55.8 kg |
| 5ft 6in | 59.3 kg | 59.2 kg | 61.3 kg |
| 5ft 10in | 68.5 kg | 66.0 kg | 66.7 kg |
Body Frame Size
Your ideal weight can vary based on frame size:
- Small frame: Lower end of healthy range
- Medium frame: Middle of healthy range
- Large frame: Upper end of healthy range
To estimate frame size, wrap fingers around opposite wrist:
- Fingers overlap = small frame
- Fingers just touch = medium frame
- Fingers don't touch = large frame
Beyond BMI: Other Measures
| Measure | Healthy Range |
|---|---|
| Waist circumference (men) | Under 94cm (37in) |
| Waist circumference (women) | Under 80cm (31.5in) |
| Waist-to-hip ratio (men) | Under 0.90 |
| Waist-to-hip ratio (women) | Under 0.85 |
| Body fat % (men) | 10-20% |
| Body fat % (women) | 18-28% |
Methodology: How Ideal Weight Formulas Work
The concept of an "ideal weight" has evolved significantly since the first actuarial tables were published by Metropolitan Life Insurance in the 1940s. These early tables were based on mortality data from policy holders - predominantly white, middle-class Americans - and defined ideal weights as those associated with the lowest death rates for each height and frame size. While groundbreaking at the time, their limitations are now well understood.
Understanding the Formulas
The Devine formula, published in 1974, was originally designed for calculating drug dosages rather than determining healthy weight. Despite this clinical origin, it became the most widely used ideal body weight (IBW) formula globally. The Robinson (1983) and Miller (1983) formulas were developed as alternatives to address perceived inaccuracies in Devine's estimates, particularly for shorter and taller individuals.
All three formulas share the same linear structure: a base weight for someone exactly 5 feet tall, plus an increment for each additional inch of height. This linear approach is a simplification - human body proportions do not scale linearly with height. Taller people tend to have proportionally longer limbs and lighter frames per unit of height, which is why the formulas diverge more at the extremes of height.
The Hamwi Formula
Another commonly referenced formula is the Hamwi method (1964), which uses: Men: 48 kg + 2.7 kg per inch over 5 feet; Women: 45.5 kg + 2.2 kg per inch over 5 feet. It also includes a 10% adjustment for body frame size - subtract 10% for a small frame, add 10% for a large frame. While less commonly used in clinical settings today, the frame size adjustment makes it slightly more nuanced than Devine alone.
BMI-Based Ranges vs Single Numbers
Modern clinical practice has largely moved away from single "ideal weight" numbers in favour of healthy weight ranges based on BMI. The advantage of the BMI range approach (18.5-24.9) is that it acknowledges a broad spectrum of healthy weights. For a person 170 cm tall, the healthy range spans from 53.5 kg to 72 kg - a difference of nearly 19 kg. This range accommodates different frame sizes, muscle mass, and body compositions far better than any single-number formula.
UK-Specific Context
The UK population's relationship with weight is shaped by specific national health policies, data, and cultural factors that differ from other countries.
NHS Weight Assessment
The NHS primarily uses BMI combined with waist circumference to assess weight-related health risk. Under NICE guidelines (CG189), adults with a BMI of 25-34.9 should also have their waist circumference measured: above 94 cm for men or 80 cm for women indicates increased risk, while above 102 cm for men or 88 cm for women indicates high risk. This two-measurement approach is more reliable than either metric alone.
Ethnicity Adjustments
Critically, NICE recommends lower BMI thresholds for people of South Asian, Chinese, and other Asian ethnic backgrounds. For these populations, overweight is defined as BMI 23-27.4 (rather than 25-29.9) and obesity as BMI 27.5+ (rather than 30+). This reflects strong evidence that these populations develop type 2 diabetes and cardiovascular disease at lower BMI levels due to differences in body fat distribution. Given the UK's diverse population, this adjustment is highly relevant.
UK Population Statistics
According to the Health Survey for England, approximately 64% of adults are overweight or obese (BMI 25+), with 26% classified as obese (BMI 30+). The average BMI for men is approximately 27.6 and for women 27.7, meaning the typical Briton is clinically overweight. Average weights are approximately 84 kg for men and 72 kg for women, compared to the Devine formula "ideals" of around 73 kg and 57 kg respectively for average-height individuals. This gap between population averages and formula targets highlights why context matters when interpreting results.
The NHS Health Check
Adults in England aged 40-74 are invited for an NHS Health Check every five years, which includes weight assessment alongside blood pressure, cholesterol, and diabetes risk. This free service identifies individuals who would benefit from weight management support. Scotland, Wales, and Northern Ireland operate similar but separate programmes.
Worked Examples
Example 1: Average-Height Woman
Height: 5ft 4in (163 cm)
Devine formula: 45.5 + (4 x 2.3) = 54.7 kg (8st 8lb)
Robinson formula: 49 + (4 x 1.7) = 55.8 kg (8st 11lb)
Miller formula: 53.1 + (4 x 1.36) = 58.5 kg (9st 3lb)
BMI healthy range: 49.2-66.2 kg (7st 10lb - 10st 6lb)
All three formulas fall within the healthy BMI range but cluster around the lower end. A woman with a medium to large frame might be perfectly healthy at 62-65 kg despite exceeding all three formula targets.
Example 2: Tall Man Who Exercises
Height: 6ft 1in (185 cm)
Devine formula: 50 + (13 x 2.3) = 79.9 kg (12st 8lb)
Robinson formula: 52 + (13 x 1.9) = 76.7 kg (12st 1lb)
Actual weight: 92 kg (14st 7lb)
This man appears "overweight" by all formula standards and has a BMI of 26.9. However, he weight-trains three times weekly and has visible abdominal definition. His waist circumference is 86 cm (well under the 94 cm risk threshold) and his body fat percentage is approximately 15%. By any meaningful health measure, he is fit and healthy - demonstrating the limitations of weight-only assessments.
Example 3: Older Woman with Osteoporosis Concerns
Height: 5ft 2in (157 cm), age 68
Devine formula: 45.5 + (2 x 2.3) = 50.1 kg (7st 12lb)
Actual weight: 52 kg (8st 2lb), BMI 21.1
While her weight appears "ideal" by formula standards and her BMI is healthy, her GP has flagged concerns. For older adults, being at the lower end of the healthy BMI range is associated with increased fracture risk and poorer outcomes if hospitalised. Her doctor recommends maintaining weight above 54 kg and focusing on protein intake and weight-bearing exercise to preserve bone density and muscle mass.
Common Mistakes and Tips
Frequently Asked Questions
Should I aim for my ideal weight if I have been overweight for years?
Not necessarily. Research shows that even a 5-10% weight loss from your current weight produces significant health benefits, including reduced blood pressure, improved blood sugar control, and lower cholesterol. Aiming for "ideal weight" when starting from a much higher weight can feel overwhelming and lead to giving up. Set incremental targets and celebrate each milestone. The NHS weight management pathway recommends an initial target of 5-10% weight loss over 3-6 months.
Why do different formulas give different results?
Each formula was derived from different study populations using different statistical methods. The Devine formula tends to give the lowest estimates for women and the highest for tall men. The Miller formula gives more generous estimates for shorter individuals. No single formula is definitively "correct" - they are all approximations. The BMI range approach is generally more useful because it acknowledges this uncertainty.
How does muscle mass affect my ideal weight?
Muscle is denser than fat, so individuals with significant muscle mass will weigh more than formula predictions suggest without any excess body fat. A DEXA scan (available privately in the UK for approximately £100-200) can measure your exact body composition, distinguishing between bone, lean tissue, and fat mass. This provides a far more personalised assessment than any weight-based formula.
Is there a difference in healthy weight for men and women of the same height?
Yes. Women naturally carry more essential body fat (approximately 10-13% essential fat versus 2-5% for men) and typically have less muscle mass at a given height. This is why the Devine and Hamwi formulas have separate equations for men and women. However, the BMI scale uses the same thresholds for both sexes, which some researchers consider a limitation - a woman and a man with identical BMIs may have quite different body compositions and health risk profiles.
Dr. Sarah Chen, PhD
Research Scientist, Public Health
Sarah holds a PhD in Public Health from the University of Edinburgh and has published research on UK health metrics and obesity trends. She translates complex medical data into practical, accessible guidance for everyday readers.