What Weight Should I Be – NHS BMI Guide for Height and Age

Finding the right weight for your height is one of the most common health questions people ask. While no single formula works for everyone, Body Mass Index (BMI) provides a scientifically validated starting point that health professionals across the UK use to assess whether your weight falls within a healthy range. Understanding how BMI is calculated, what the numbers mean, and how UK-specific tools can help you interpret your results is essential for making informed decisions about your health.

The NHS offers free calculators that allow you to input your height and weight in either kilograms or stones, instantly categorising your result as underweight, healthy, overweight, or obese. However, these tools come with important caveats that this guide will explain in detail, helping you distinguish between what’s useful and what requires further professional advice.

Whether you are looking for your ideal weight as a female, seeking UK-specific charts that account for ethnic background, or simply wondering what weight you should be at your current height, this comprehensive guide covers everything you need to know with verified NHS data and World Health Organization guidelines at its core.

What weight should I be for my height?

BMI works by dividing your weight in kilograms by the square of your height in metres. For example, someone weighing 70kg at 1.70m tall would calculate as 70 ÷ (1.70)², yielding a BMI of 24.22. The NHS adult calculator accepts measurements in feet and inches as well as centimetres, and stones alongside kilograms, making it accessible to all UK residents.

• BMI is calculated using weight divided by height squared, providing a standardised measure across populations.
• The healthy BMI range spans 18.5 to 24.9 kg/m² for most adults, according to World Health Organization guidelines.
• BMI does not directly measure body fat, meaning muscular individuals may receive misleading “overweight” labels.
• The NHS BMI tool adjusts for ethnic background, as people of South Asian, Black African, African-Caribbean, or Middle Eastern descent face higher health risks at lower BMI values.
• Waist circumference should accompany BMI readings; measurements above 94cm for men or 80cm for women indicate increased health risk requiring action.
• No single “ideal weight” exists because individual factors including bone density, muscle mass, and body composition vary significantly.

Ideal weight for 5’4″ female in kg

A woman standing at 5 feet 4 inches (162.6 cm) falls within the healthy BMI range at weights between approximately 49.2 kg and 65.8 kg. This translates to roughly 7 stone 11 pounds to 10 stone 5 pounds. The midpoint of this range, around 57–58 kg (approximately 9 stone), often represents a practical target for many women of average build.

However, Bupa’s calculator provides personalised ranges by asking for your exact height and weight, then suggesting a healthy weight corridor rather than a single figure. This approach reflects medical consensus that a range is more useful than a single “ideal” number.

Ideal weight for 5’7″ female in kg

Women measuring 5 feet 7 inches (170.2 cm) should aim for a healthy weight between approximately 53.6 kg and 71.7 kg, corresponding to roughly 8 stone 6 pounds to 11 stone 4 pounds. NHS-linked ideal body weight tables confirm these figures, with the lower end of the healthy BMI range representing a baseline for those without significant muscle mass.

Athletes or individuals with above-average muscle mass may comfortably sit higher in this range without carrying excess body fat. Consulting a GP or registered dietitian provides personalised guidance that accounts for these individual variations.

Ideal weight for 5’9″ male in kg

Men at 5 feet 9 inches (175.3 cm) have a healthy weight range of approximately 56.8 kg to 76.0 kg, or roughly 8 stone 13 pounds to 12 stone. NHS Ideal Body Weight tables corroborate these figures, noting that men at this height typically carry an ideal weight around 68 kg (10 stone 10 lb) when considering average body composition.

The Forum Health Centre height-weight chart, which links to NHS resources, emphasises that these figures apply to adults aged 18 and over who do not have highly muscular builds.

What weight should I be female?

Women often search for specific weight targets that account for female physiology, which differs from male physiology in fat distribution, hormonal influences, and metabolic rate. While BMI does not differentiate between sexes in its calculation, the results apply equally, though women naturally carry higher body fat percentages as a percentage of total weight.

The NHS 111 Wales BMI calculator accepts measurements in stones and pounds, catering to UK preferences, and provides category labels including underweight, healthy weight, overweight, and obese based on WHO thresholds.

What weight should I be by age?

Adult BMI does not factor in age, which creates a known limitation. Research published by the Centres for Disease Control and Prevention acknowledges that muscle mass typically decreases with advancing age, potentially skewing BMI results for older adults who may appear heavier relative to their body fat.

For children and teenagers aged 2 to 17, the NHS children’s BMI calculator accounts for age and sex at birth, comparing results against UK growth charts developed by the Royal College of Paediatrics and Child Health. This ensures growing bodies are assessed against age-appropriate benchmarks rather than adult standards.

What is my ideal weight in stones for my height and age?

UK residents commonly think in stones rather than kilograms, making it essential to translate ranges into familiar units. A healthy weight range of 55–74 kg converts to approximately 8 stone 9 pounds to 11 stone 9 pounds for someone of average adult height. This conversion depends entirely on your specific height, which is why using the NHS calculator with your actual measurements produces the most useful result.

The NHS Tayside Ideal Body Weight table provides gender-specific ranges in kilograms with obese thresholds, useful for those seeking more granular data beyond simple BMI categories.

What weight should I be calculator?

Online BMI calculators offer the most convenient way to determine whether your current weight falls within a healthy range. The official NHS BMI calculator serves as the recommended starting point, having been developed by health professionals and regularly updated to reflect current medical guidance.

Ideal weight calculator in kg

When using any calculator, input your height accurately, ideally measured without shoes against a wall. Enter your weight in the unit you prefer, whether kilograms or stones and pounds, since the calculation converts units internally.

After receiving your BMI result, the NHS calculator prompts you to measure your waist circumference, which provides additional context. Men with waist measurements exceeding 94 cm or women exceeding 80 cm should consider weight management strategies, while measurements above 102 cm for men or 88 cm for women indicate substantially elevated health risks.

What is my BMI?

Understanding your BMI involves more than simply knowing the number. A BMI below 18.5 classifies you as underweight, which may indicate nutritional deficiencies or underlying health conditions requiring medical attention. The healthy range of 18.5 to 24.9 represents the zone where most health risks associated with weight are minimised, according to UK government health publications.

BMI values between 25 and 29.9 indicate overweight status, associated with increased risk of type 2 diabetes, heart disease, and certain cancers. Values of 30 or above place you in the obese category, where clinical intervention and lifestyle changes become medically advisable. Deerbrook Surgery’s BMI tool, which links to NHS resources, specifically recommends that individuals scoring 30 or above contact their GP for personalised assessment.

What weight should I be UK?

UK-specific weight assessment tools account for regional factors including ethnicity, which significantly influences health risk thresholds. The NHS calculator specifically adjusts healthy BMI boundaries for individuals from South Asian, Black African, African-Caribbean, and Middle Eastern backgrounds, as research demonstrates these groups face elevated health risks at BMI values that would be considered healthy for white British populations.

For adults from these backgrounds, a BMI of 23 rather than 25 represents the threshold above which health risks begin increasing. This adjustment appears automatically when using the NHS calculator, making it essential for accurate self-assessment among UK minority populations.

NHS weight chart

The NHS publishes weight charts that translate height measurements into healthy weight ranges, categorised by gender. These charts draw from the same BMI data underlying the online calculator, providing a quick reference for those who prefer visual tables over interactive tools. The charts explicitly note they are unsuitable for very muscular individuals, pregnant women, or those with height-affecting medical conditions.

A sample from NHS-linked sources shows that women at 150 cm (approximately 4’11”) should maintain weights between 45.5 kg and 54.6 kg for ideal body weight, with obesity risk emerging above that range. These figures align with the broader BMI methodology while providing practical targets in commonly used units.

Average male weight UK

According to government health data, the National Diet and Nutrition Survey, the average adult male in the UK weighs approximately 84 kg (13 stone 3 lb), with average heights around 175 cm (5’9″). This average weight falls in the overweight BMI category, reflecting broader population trends that the NHS aims to address through public health initiatives.

Women in the UK average approximately 69 kg (10 stone 11 lb) at an average height of 162 cm (5’4″), placing the population average similarly in the overweight category. These figures contextualise individual targets, showing that “average” does not equate to “healthy” in national health terms.

BMI chart men

BMI categories apply equally to men and women, though men statistically carry more muscle mass, which can artificially inflate BMI readings. For men who weight train regularly, waist measurement provides a more accurate health risk indicator than BMI alone, since significant muscle development naturally increases weight without adding health risk.

Male-specific NHS guidance emphasises that waist circumference above 94 cm requires lifestyle attention, while measurements exceeding 102 cm indicate high-risk status necessitating professional support. This approach bypasses BMI limitations for those whose weight reflects muscle rather than excess fat.

How BMI standards have evolved over time

BMI as a health metric originated in the 19th century when Belgian mathematician Adolphe Quetelet developed the formula to assess population-level obesity. The World Health Organization formally adopted BMI categories in the 1990s, standardising thresholds across international health research and clinical practice.

1. 1830s: Adolphe Quetelet develops the BMI formula (then called the Quetelet Index) to describe population-level weight patterns.
2. 1972: Researcher Ancel Keys renames the metric “Body Mass Index” and validates it against population health data, distinguishing it from simple weight tables.
3. 1985: NHS begins incorporating BMI into public health guidance as scientific consensus builds around its utility.
4. 1995: WHO publishes formal BMI category definitions, establishing the 18.5–24.9 healthy range and categorical thresholds for underweight, overweight, and obese.
5. 2006: NHS calculator introduced online, democratising access to personalised health assessment using accepted BMI methodology.
6. 2019–present: Growing recognition of BMI limitations leads to supplementary tools, including waist-to-height ratio calculators and ethnic background adjustments.

What we know and what remains unclear about ideal weight

BMI versus ideal body weight: understanding the distinction

BMI and Ideal Body Weight (IBW) represent different approaches to assessing healthy weight. BMI provides a ratio applicable across entire populations, while IBW tables offer specific weight targets based on height and gender that were originally derived from insurance industry data rather than direct health outcomes research.

The NHS Tayside IBW table presents columns for both ideal weight and obese threshold weights by height, recognising that healthy weight is a range rather than a single figure. These tables show that a 150 cm woman has an ideal weight around 45.5 kg, but does not become obese until exceeding 54.6 kg, illustrating the practical width of the healthy zone.

Neither metric accounts for the full complexity of human health, which is why healthcare professionals use BMI as a starting point rather than a definitive diagnosis. Individual assessment considering family history, lifestyle factors, and existing health conditions provides the most complete picture of what weight target serves any particular person.

WHO guidance states: “BMI is a simple index of weight-for-height that is commonly used to classify underweight, overweight and obesity in adults. It is defined as the weight in kilograms divided by the square of the height in metres (kg/m²).” This categorical system applies globally while acknowledging the need for supplementary measures in clinical assessment.

NHS guidance emphasises: “BMI is a useful estimate of body fat for most adults aged 18-65. It is not appropriate for pregnant women, growing children, the elderly, or athletes with high muscle mass.” This clarification addresses the most common misconceptions about what BMI can and cannot tell you about your health.

Summary and next steps

Determining what weight you should be requires moving beyond simple numbers to understand how height, gender, ethnicity, and body composition interact to affect your health. The official NHS BMI calculator provides the most reliable starting point for UK residents, offering results in both kilograms and stones with appropriate adjustments for ethnic background.

While no single formula captures everything about what constitutes your ideal weight, combining BMI results with waist measurement provides substantially more actionable information. If your calculations indicate you fall outside the healthy range, consulting your GP offers personalised guidance that accounts for factors online tools cannot fully assess.

For those with non-standard builds, including athletes and bodybuilders, investigating how professionals in physically demanding careers manage their weight may provide useful context, though individual medical advice always takes precedence over general guidance.

Frequently asked questions