Healthy Weight by Age — Weight by Age Chart & Calculator

Healthy Weight by Age — Why Age Isn't the Main Factor

Searches for healthy weight by age are common, but here's the key fact the NHS is clear about: the healthy BMI range of 18.5 to 24.9 does not change with age for adults aged 18 and over. What does exist, and what this page compares, is weight by age in the sense of population averages — how much people of different ages in the UK actually weigh on average — which is a different thing entirely from what's medically considered healthy.

This distinction matters. UK population average weight has risen over recent decades and, for several age groups, now sits above the NHS healthy BMI range at typical UK heights. That means simply matching the "average" for your age is not the same as being at a healthy weight. This calculator shows you both figures side by side, so you can see the difference clearly for your own age group and height.

For a height-first lookup rather than an age-first one, see our healthy weight by height chart. For an interactive range with ethnicity adjustment, use our healthy weight range calculator. For your overall BMI score, use the main BMI Calculator NHS.

How to Use the Healthy Weight by Age Calculator

1. Select your age group from the list.
2. Select your sex — UK population averages differ between men and women.
3. Optionally enter your height to see your personal NHS healthy weight range alongside the population average.
4. Select Show My Weight by Age Comparison to see both figures side by side, with a clear explanation of what each one means.

UK Average Weight by Age — Reference Chart

The table below shows approximate UK adult population average weight by age group and sex, based on trends from NHS Digital Health Survey data. Remember: these are averages, not healthy targets.

Figures are approximate averages, illustrative of UK population trends, and rounded for clarity. They are not a healthy weight recommendation — see the worked example below for why.

Worked Example

Take a 45-year-old man who is 178 cm tall. His age group's UK population average weight is approximately 87.5 kg. Using the standard NHS BMI formula, his personal healthy weight range at 178 cm is approximately 58.6–78.9 kg.

Interpreting Weight by Age — What Actually Matters

• Your healthy weight range doesn't shift with age: the NHS BMI band of 18.5–24.9 applies at 20, 50 or 80, based purely on your height.
• Population averages are context, not a goal: use them to understand trends, not to set a personal target.
• Body composition changes matter more than the number on the scale: muscle loss with age (sarcopenia) can occur even when weight stays the same — see our BMI vs body fat percentage guide.
• Older adults (65+): unintentional weight loss is often a bigger concern than a moderately raised BMI — always flag unexplained weight loss to a GP.

Common Mistakes About Weight and Age

• Assuming "average" means "healthy": as the worked example shows, UK population averages often sit above the healthy BMI range.
• Thinking healthy BMI thresholds shift with age: for adults, they don't — the same 18.5–24.9 band applies throughout adulthood.
• Ignoring muscle loss: stable weight can mask a shift from muscle to fat as people age — strength and mobility matter alongside weight.
• Applying this guidance to teenagers: under-18s need NHS growth centile charts, not adult weight-by-age comparisons — see our child growth chart calculator UK.

Benefits and Limitations of Weight-by-Age Comparisons

Benefits

• Provides useful population context for how weight trends shift across adulthood
• Highlights clearly that "average" and "healthy" are not the same thing
• Combines population data with your personal NHS healthy weight range in one view
• Flags age-specific considerations, such as the importance of avoiding unintentional weight loss in later life

Limitations

• Population average figures are broad estimates and vary by data source and year
• Averages don't reflect individual differences in muscle mass, frame size or health status
• Not designed for children, teenagers, or pregnant women
• Should be used for context and understanding only, not as a personal target

Weight by Age vs Weight by Height: What's the Difference?

Real-Life Example: Two People, Same Age, Different Story

Consider two 60-year-old women, both 162 cm tall. The UK population average weight for their age group is approximately 73 kg. The first woman weighs 73 kg exactly — matching the average — but her personal healthy weight range at 162 cm is roughly 48.6–65.3 kg, meaning she is actually above the NHS healthy range despite being "average" for her age.

The second woman weighs 62 kg, below the population average but comfortably within her healthy range. By population-average standards alone, the second woman might seem "underweight for her age" — but by NHS BMI standards, she is the one within the healthy range. This illustrates precisely why height-based healthy weight, not age-based averages, should guide personal health decisions.

Expert Tips

• Use your height, not your age, as the basis for a personal healthy weight range
• Treat population averages as background context, never a personal goal
• From your 40s and 50s onward, pay attention to strength and muscle mass, not just the number on the scale
• If you're over 65 and losing weight without trying, speak to your GP promptly
• Combine this page with our waist to height ratio calculator for a fuller picture that isn't affected by age-related muscle changes in the same way as weight alone

Sources & References

• NHS Digital — Health Survey for England: NHS Digital
• NHS Live Well — Healthy Weight: nhs.uk/live-well/healthy-weight
• NICE Guideline CG43 — Obesity: Identification, Assessment and Management (2023): nice.org.uk/guidance/cg43
• NHS — Sarcopenia and muscle loss in older adults: general NHS ageing and frailty guidance

Frequently Asked Questions — Healthy Weight by Age

Conclusion: Healthy Weight by Age, in Perspective

The most important takeaway about healthy weight by age is that, for adults, healthy weight isn't really determined by age at all — it's determined by height, using the same NHS BMI range of 18.5 to 24.9 whether you're 20 or 80. Weight by age population averages are useful for context, but as the worked examples on this page show, they often sit above what's actually considered a healthy BMI.

For your own personal healthy weight, based on your height rather than population averages, use our healthy weight by height chart or the main BMI Calculator NHS. If you have concerns about weight change at any age, particularly unintentional weight loss in later life, speak to your GP for personalised advice.